Solved: Slow Transfer Speeds on Synology NAS

Solved: Slow Transfer Speeds on Synology NAS

So you’ve got a shiny new Synology NAS and you’ve started storing files on it, videos, music and so forth.  Unfortunately, the file transfer speeds are so bad you’re considering buying a turtle and glueing a USB drive to its back to speed up file copying.

After hours of searching the net for an answer, in the end, I found the cause of my woes in a couple of little settings tucked away on the Synology – effectively my Synology NAS wasn’t even trying to use newer/faster versions of the SMB protocol.

To find and check this, perform the following steps:

Login to the Synology NAS and click on Control Panel:


Ensure that the SMB service is enabled then click Advanced Settings:

In Advanced Settings, set the Maximum SMB protocol to SMB3, I also increased the minimum SMB protocol to SMB2.  If your NAS is operating on a private home network, you may want to disable transport encryption mode (use at your own risk) and enable opportunistic locking:

For me on my Synology DS215j, this took my file transfers from around 5MBps to around 80MBps!

For anyone looking for a better network platform for home, check out my article on Ubiquiti’s Unifi kit:

Bob McKay

About Bob McKay

Bob is Director of Operations at Perfect Image, a full time father and husband, part-time tinkerer-with-wires, coder, Muay Thai practitioner, builder and cook. Loves love, tolerance and co-existance. Hates hate. Is aware of the irony of hating hate.

Disclosure Policy

151 comments on «Solved: Slow Transfer Speeds on Synology NAS»

  1. Margaret says:

    Is it necessary to reboot after making the changes? I have the DS218j. First I had used Disk Station to do a 2-way sync on my desktop for the Pictures folder. SLOW. Next I synced the Music folder. Relatively faster. Now I am attempting to sync the Music folder on my tablet (SSD) remembering how much quicker the transfer was on the desktop. File transfer rate = 1 file every 8 minutes. It’s been several days and 473 files remain. This is beyond painful. Many other descriptive words. So in short, I’d like to try these changes now w/o having to start all over because of a required reboot. Thank you!

    1. S400 says:

      Tried this change to SBM settings myself – on a DS918+.
      It has made absolutely no difference whatsoever – even though the LAN connection on the NAS swears it is connected at 1000Mbpds , full duplex with MTU = 1500.
      MTU size is the same on the PC..

      1. brendaonmiddle says:

        I tried a multitude of “fixes” when my DSM 418 went from 100 Mb/s to 10 MB/s. Synology was showing Network/Network Interface/Network Status: 1000 Mb/s, Full Duplex, 1500 MTU.

        When I checked Win 10 Pro/Control Panel/Network and Internet/View network status and tasks/Ethernet, Speed was showing 100 Mb/s.

        Clicking on Properties/Configure/Advanced and drilling down to Speed & Duplex, there was the culprit:100 Mb/s Full Duplex. Changing that to 1.0 Gb/s Full Duplex, saving, and giving the Network Adapter a few seconds to adjust resulted in consistent transfer speeds of 100-115 Gb/s.

        Of course, one’s ethernet adapter has to be capable of 1 Gb/s.

        The lesson here is that just because your DSM shows a certain Speed does not mean that the host is transmitting at that speed.

        1. Bob McKay says:

          Thanks for posting – its unusual for a Windows network adapter not to autonegotiate up to the highest available speed. The only time I’ve seen it not do this is when there’s a problem with a cable, driver or hardware (and I haven’t seen this for many years), hopefully this is the end of it the problem for you but if you do see any weird errors or network problems, might be worth taking a closer look at that network cable).

        2. Thanks for having me check, my Synology had downgraded itself to a 100-megabit connection, checked the cable at the switch and unplugged and re-plugged the one on the Synology and it was back at gigabit. I was trying everything to figure out why USB transfers were faster than LAN after a recent volume expansion completed.

          1. Bob McKay says:

            Hi Kacey,

            Glad you sorted it – I’d check on that network cable if I was you though, I’ve only seen network speeds negotiate down when there’s a cable or connection issue.

    2. Ryan says:

      I applied the settings, but made no difference, even after 5 mins. Rebooted NAS, and now performance is back to full speed, like when this issue randomly appeared about 3 years ago. THANKS!

  2. Margaret says:

    Got my answer. When attempting the change, “Network Service will restart”. Guess I need to be patient….

    1. Micheal Espinola says:

      For anyone wondering, you can do this live. Your time machine backup or file transfers will quietly recover from the extremely brief disconnect. Networking at this level recovers all on its own. You’ll quickly see your time machine backup estimated time drop soon afterward.

      1. Stephen says:

        Yeah – wow!
        I was doing an rysnc at 7.56MB/s. As soon as I hit apply (well, at least I didn’t notice anything pause), it jumped to 63MB/s!

        The strange thing is, before I expanded my volume from 1 disk to 3 I was getting 30-40 MB/s

        1. Stephen says:

          Scratch that – the network disruption unmounted the share and Ubuntu wrote to the root disk.
          Turns out my network cable clip is broken, and somehow dislodged just enough to go to 100Mbit. At 1000Mbit, I’m getting 17 MB/s – still rather useless really compared to the single disk speed.
          Internal file copying was 40MB/s and a Mac client was about 50MB/s, so it’s just something that Ubuntu got upset about…

          (I’m up to 32MB/s with normal file copying instead of rsync…)

          1. Remi says:

            I’ve been fighting with this issue for weeks… broken network cable clip was the culprit! hahahahahaha *barf*

          2. Bob McKay says:

            LOL – I feel your pain. I once had a customer network that had an intermittent fault but the switch wasn’t smart enough to diagnose where the problem lay. In the end it was a faulty NIC on the laptop of a travelling/roaming user.

  3. Will says:

    Thanks! Just wanted to comment for others that might stumble upon this. Don’t have a gigabit router so was looking for other options to speed up my 1.5mb/s speed. This really worked – cut a 90gb move from 16 hours to 3 hours.

    1. Bob McKay says:

      Hi Will,
      Glad it helped! 🙂

  4. Matt says:

    I was really hoping that would be the answer to my problem… unfortunately it didn’t do the trick 🙁
    However, my settings wasn’t setup as you prescribe. So I hope that a step in the right direction.
    Thanks for that.

  5. Giordano Bruno says:

    Good morning. Your hint made my month!
    Slow speed has been a problem for years for the 1812+: the max. was 25 at its best …
    I was even considering changing it for a newer model.
    Now speed is up to 110 which is perfect.
    Again: Thank you very much and all the best for you and your family.

    Giordano Bruno

    PS What is the transport encryption mode? What if I unable it?

    1. Bob McKay says:

      Hi Giordano, I’m glad it helped! The transport encryption mode adds encryption to SMB V3.0 for security but obviously like any encryption, it comes at a cost so may affect your top speed it its enabled (try it and see!).

  6. Ming says:

    Very helpful. Save my day. Almost return. Synology should put this on their site

      1. Bob McKay says:

        Thanks for the link! I think this must be new as they never used to have anything on their site.

  7. Cub says:

    The hints not work for me, still only getting 10.5MBs max transfer,
    Any advise?

  8. Clay Burch says:

    I can’t even access my nas. It keep saying authorisation required. Any suggestions???

    1. Bob McKay says:

      Hi Clay,
      I’m afraid if you’ve lost the credentials to your NAS you have a whole other problem my friend!
      If you can browse to network shares though, your computer must have some saved credentials you may be able to retrieve.

    2. GC says:

      Clay, There is a reset button on the NAS. Use it VERY CAREFULLY. The Synology web site will say something like hold BRIEFLY and it will reset the password. If you hold it too long it will do a complete reset and you will lose your data. So please, READ the web site first.

      1. Bob McKay says:

        Hey GC, Thanks for the useful comment!

  9. Sanjay says:

    How long do I have to wait for the \\Diskstation share to come back? Currently says “The Network path was not found”…

    1. Bob says:

      Reboot the PC after the change. I had the same issue and that resolved it for me.

  10. Craig says:

    You legend!!!! Cant believe Synology don’t advise this info!

  11. Adam says:

    I recently purchased and installed a Synology DS418play NAS, using WD 4TB RED drives. After finding Mr McKay’s page on the interwebs,I made the same changes to my NAS as listed above.

    Yet, it hasn’t solved the speed transfer issues. When moving three (3) ~4GB files from a PC to the NAS, with the NAS mapped as a network drive, the initial transfer speed is great…some 106mb/sec (Ihave the two NICs bonded, on a gigabit switch). Then, within a few minutes, the transfer rate falls off a cliff, dropping down to 5-6MB/sec.

    It appears to be an issue during a multiple file transfer, not a single file transfer.

    1. Bob McKay says:

      Hi Adam,

      When you say the issue seems to be when you’re transferring multiple files, are they concurrent or queued? I’m wondering if concurrent copies of large files will have the hard drive head dancing back and forth and it could be the slow down you’re seeing is the caches maxing out. What is your RAID configuration and do you see the same problems copying the same 3 files back to your PC *from* the NAS?

      1. EB says:

        Honestly, I want to throttle the people who suggested I buy a NAS and the replacement supposedly ‘better and faster one’. What a waste of money. I’ve spent the last 5 days trying to upload, transfer and get everything running and syncing smoothly!

        1. Bob McKay says:

          Erm … thanks for the comment Em.

        2. steve says:

          call me 🙂

  12. MB says:

    Hi, thank you very much, I’ve been seaching on the web for couple of hours before finding your solution. It works for me!

  13. Brandon says:

    Recently installed a DS218, and the upload speed is awful. I made the changes above and I’m still getting upload speed in the single digit KBs range. At this rate, it will take a century or more to transfer my terabytes of photos. Do you have any other suggestions?

    1. Bob McKay says:

      Hi Brandon, what have you tried and what is our setup? (e.g. Mac, PC, Wired, Wireless)

      1. Brandon says:

        Hi Bob, thanks for your response. The DS218 has a wired connection to my Netgear R7000 router. All of my computers are running Win 10. One desktop is also has a wired connection, but the computer where I store the majority of my data is connected via wi-fi (2.4GHz). So far, I’ve tried changing the settings specified above and rebooting. Upon rebooting, the upload speed jumped up to 175Kb/s…very briefly, alas. It then returned to <10Kb/s…

        Could it be the CAT5 cable I'm using?

        1. Bob McKay says:

          Hi Brandon,
          I doubt very much that the problem lies with the cable between the Netgear and the Synology but given both have Gigabit ports its probably worth putting a CAT6 cable in there anyway (negligible cost too). The speeds your seeing are so slow however that something else is amiss here and I’m guessing the issue is around the wifi. Have you done a test transfer from the PC that is connected to the Netgear via a cable? This should prove (or disprove) that the connection from the Netgear to the Synology is sound. What signal strength is your computer seeing? If you do a browser based broadband speed test on that computer, what speeds do you see? (I ask because that should theoretically show you the slowest speed on the whole chain which given the speeds above appears to be within your home network).

          1. Brandon says:

            Hi Bob,
            I was playing with it again last night and this may be a case of user error. I discovered the upload queue and got better visibility on what what happening. I did what you suggested about moving a single file (2GB) from the wired computer to the NAS, and it transferred in about 2 minutes. I tried the same file from wifi and got a similar result. I’m now moving the folders in smaller pieces (40-50GB at a time). Upload speeds bounce around between 1-5 MB/s…is this normal?

          2. Bob McKay says:

            Hi Brandon,

            There’s still a lot of factors to consider I’m afraid but the critical one is that MBps is not the same as Mbps (its all in the case), a MegaBYTE is eight times larger than a Megabit. If you are using, for example, the Wireless-G (since you said your wifi 2.4Ghz) then the theoretical link speed is 54Mbps (Megabits) now in reality this equates to a 25Mbps transfer rate. To measure this in MegaBYTES you need to divide it by 8 so we’re talking around 3MBps.

            The truth is, if you want to do heavy lifting in terms of file transfer you either need a cable or a dual band wifi. Personally I swear by Ubiquiti Wireless Access Points, the pro versions of which give me a real-world transfer speed of around 25 MegaBYTES per second.

        2. Neal says:

          I had the same problem with the DS218+, I was transferring a ~100 GB folder with lots of tiny PDFs and it was running at around 10 to 50 Kbps. The way I solved it was to zip up the whole folder and transfer it at once, which reduces the size slightly but I think the major gain is that there must be some overhead in opening and closing a transfer connection in the Synology software. Once, the transfer was finished I extracted the ZIP file on the drive. It’s not ideal but gets the job done.

          1. Bob McKay says:

            Hi Neal,

            I think this is really a general issue not just Synology, I used to see this all the time when copying websites across servers, etc. (as they tend to hundreds/thousands of tiny files), just zipping it use to drastically reduce the time on both Linux or Windows systems.

  14. Brandon says:

    Hi Bob,
    Thanks for the advice and information. Continued testing over the weekend, looks like it’s working well. I switched the wifi to 5Ghz (802.11ac according to the router manual) and uploads are generally 5-10 MBps (not Mbps) according to the upload queue. The key is to not try moving terabytes in one chunk, I think. I moved a couple folders >150GB and upload times were in the 12-24 hr range. Anyway, thanks again!

    1. Bob McKay says:

      Hey Brandon,
      I’m glad things seem to have sped up. One thing I hadn’t considered is that when copying multiple files from my PC I never do ‘concurrent’ copies, that is where you set a file copying, then separately set another copying, then another, etc. – this is because Windows isn’t smart enough to just push each additional file to a queue, it copies a chunk of each in a cycle, which means there’s a bigger admin overhead (and if you have an old HD, the read head will be jumping about a lot more). If you need to copy multiple files, I’d only do it where you are able to select them all at the same time and do a copy/paste (sometimes I’ll even move files on my PC to the same folder before moving them to my NAS to facilitate this).
      All the best

  15. johnrxx99 says:

    It worked for me. But why did it need to be changed – I was at 112 Mbps then dropped to 12Mbps for no apparent reason.

  16. Roger says:

    Thanks a lot, it brought me from 10 to 110 MB/s – been waiting so long to copy the files for a year until I googled and found this forum 😀

  17. andy says:

    hi bob my ds215j wit 2x10tb hdd in shr buut when i try and copy my 1Tb acronis system back up to usb hardrive im luck get 6MB/s which is slow when this drive does 80MB/s plus on my usb3 on pc. Your fix did not speed it up dsm 6.2… fully up to date

    1. Bob McKay says:

      Hi Andy,

      Thanks, just to be sure, are you copying over USB, wifi or ethernet? Samba (SMB) is a network protocol you see.

  18. Martin says:

    You, my good sir ROCK!
    Been uploading photos for days. Now I’m done in a matter of hours.
    Thanks a bunch and cheers

    1. Dan says:

      Hi Bob, I come.across your page when I am searching for a solution to the slow transfer. I have just got my DS918 and setting it up. Tried transfer a drama download and speed was like 3MBps. I did as what you have shown. But it hasn’t turn for the better. Do I need to do a power down reboot for my DS918..? Many thanks…

  19. Graham says:

    Thanks for this, new NAS and couldn’t understand why it was so slow on transfer. Applied your settings and rebooted, all is good. Thank you sir!

  20. Robert says:

    Great post. I was getting 4MB/s upload to the NAS drive from my laptop on wireless.
    Adjusted all parameters as listed above and that still didn’t work.
    Finally changed wireless to 5G and that made it jump to 10 MB/s for smaller files and 40MB/s for larger video files.
    I am sure more fine tuning to be done but it’s very usable now.


  21. RetroC says:

    Tried the settings suggested above but unfortunately did not have change anything for me.
    I have a DS218+ wired to router. Used to access it via powerline (650 Mbps) from my PC and got around 110 MB/sec.
    “Upgraded” my WiFi and now use Asus wifi card (Triband) to connect to TP-link Archer VR2800 router. Windows suggests the WiFi connection speed is 1700 Mbps which I was hoping would give me similar results to powerline. My current file transfer speeds are 5-8 MB/sec which is slower than my broadband. I think its a settings issue as file transfer between my Laptop and PC over WiFi are around 30 MB/sec. I have tried to switch from SMB to FTP but no change in speeds. Is there something I am missing. Any suggestion will be appreciated.

    1. Bob McKay says:

      I’d try the Powerline again (with the far end plugged in to the new Archer router), the idea being to to test the throughput from the Archer to the NAS (if its as fast as it used to be, you know its a problem with your wireless connection rather than that link or a protocol issue. Assuming that the test shows fast speeds via the Powerline, I’d try a couple of different options for connecting via wifi if you can (diff adapter, tablet, mobile, etc.) and see what throughput you get. All I can think of I’m afraid!

  22. SyVo says:

    Thank you! It work great.

  23. Trueqap says:

    :)) Thank you!

    from 40 to 780 MB/s with 5g WIFI!

  24. Alex says:

    I recently bought the 918+. I have it and my previous Synology connected at the same gigabit ethernet switch (older version of TP-Link’s TL-SG1005D), however even after adjusting the Network settings on both Synology DSs, the transfer rate is still around 3 MB/s. Nothing has changed. How can I doctor this (I have no problem exchanging parts of the hardware) to finally get solid transfer rates between them?

    1. Bob McKay says:

      Hi Alex,
      Too many unknown factors here to be able to offer any advice I’m afraid:
      Where to/from are you doing the copies? (device types, etc)
      What type of connections are the devices using (I’m assuming the Synology units are wired but if using a PC, is that on wifi?).
      Have you checked resource monitor to see what speeds the Synology units say they are connected at? (if you have a bad cable, it could still be negotiating to 100Mbps even if both sides are capable of Gigabit).

  25. Carlos says:

    Hi Bob, I followed your recommendation but the issue persisted and my write/reads were still slow on a Macbook.

    However, switching from afp://…. to smb://… seems to have done the trick; speeds jumped from 5MB/s to around 100MB/s.

    Sharing just in case someone else forgets that this trick is for smb. Like I did!

  26. Jose Mercado says:

    For those still having the issue, as it does not apply to your setup. If you have dedicated 10GB connection to your NAS, make sure your iSCSI Targets are set to bind to those network cards. If all Networks are selected, you will notice that speeds will not always work as expected as it would be binding the connection to the slower Network card interface.

    go to your iSCSI manager, select the target section, select your Target and Edit. In there Select the Network Binding tab and use the “only selected interfaces” and check only the desired high-speed interfaces on the list. Bingo! now you have the expected speeds. Synology has a fantastic write up on MPIO (multipath) as well that is easy to follow.

    The above answer asumes you have properly configured the network interfaces on your server and NAS.

    1. Bob McKay says:

      If that’s your home-setup I have serious geek-envy!! 🙂

  27. JP says:

    You ar a legend. Went from around 20 up to 120! So a quick courtesy to say thank you.

  28. pickles says:

    I had already put the SMB3 & 2 min & max, but hadn’t disabled Transport Encryption Mode and now i’m uploading over wifi at 15 MB/s and have uploaded 2 gig in a few minutes, which took an hour before. So Thanks!

    The only thing i’m not sure about is I still have the ‘Enable SMB2 Lease’ ticked, as when I went to untick it, it warned “If you disable SMB durable handles or SMB2 lease, the Bonjour Time Machine broadcast via SMB will be disabled”. Which sounded bad as this is a Time Machine backup i’m doing so I left it ticked for the time being. Will that make much difference? Oh, i’m on Mac.

    1. Bob McKay says:

      Hey Pickles, glad this helped. Regarding the Time Machine Broadcast I’m afraid I’m not an Apple guy so can’t help, hopefully someone else here may know.

  29. Paul says:

    I want to use my Synology DS718+ to backup 2 Win 7 PC’s, one with an Ethernet link (PC-1) the other wireless (PC-2). Each PC has an external USB drive and a NAS user folder mapped as a PC drive. I can’t do unattended late night automated backups since the NAS maps disconnect after some idle period. I did a backup on PC-1 to it’s external USB drive and copied the 110GB file to the NAS drive at a good rate in about 45 min. That won’t work for PC-2 since the wireless transfer rate is far too slow. I’m thinking about adding a PowrLine Ethernet link from my Router to PC-2 (no easy way to run a cable) and would appreciate any thoughts on this.
    I also have 3 more PC’s I want to connect and am thinking of adding an 8 port Ethernet switch but not sure if I can still set fixed IP’s for each user.

    1. Bob McKay says:

      Hi Paul,

      This really depends on the type of backup you’re doing, these days I generally ‘image’ my PCs shortly after a clean installation and manually copy the image to the NAS. After that, just backup documents, etc. to the NAS directly on a schedule. You should need to map network drives, just create a shared folder on the Synology and use the UNC path to it (\\NASNAME\SHAREName\) – provided your machines are using your local router for DNS, this should work fine. In terms of fixed IP addresses, again you should really need them – just use the UNC paths of the PCs (e.g. \\PC1\). I’ve used powerline adapters quite a bit as my previous apartments were solid concrete & rebar, they worked pretty well and from what I read, they have gotten a LOT faster since then. Just remember that the sockets generally need to be on the same phase and sometimes you can get interference from other equiment (I used to have a cheap laptop power adapter that would kill powerline connections when it was plugged in to the same ring main).

  30. jp says:

    these settings did nothing for me. Still in the sub 10 b/s, transferring 1GB takes almost an hour.

    1. Bob McKay says:

      Hi JP,
      This seems like something else is going on there, without any details its impossible to help however. For example is it wired or wireless, what is the theoretical speed of the connection, what operating system are you running and what is the data your copying (e.g. 1 1GB file or 1000 1MB files)

  31. Smithers says:

    Nice info! I have a DS216SE and since a week or 3 transfer files is so slooooow. It start 2 sec with 30mb and then drops to 1mb and 366kb and 0, back to 1/2mb and 366kb and 0…..after checking i’m seeying my diskspaces runs up to 100% and i think that is the bottleneck. I have 2 reolink camera’s attached but i disabled them testing and no difference. I tried your stuff above but nothing seems working….any suggestions? thanks in advance!

  32. Rxs says:

    hi.. this seems to be a productive thread,,
    I’ve searched high and low for the issue i have!
    I’ve got the Synology DS418Play with four 2TB Seagate Ironwolf NAS drives. even with a direct wired connection to the NAS, I am unable to get more than 10mb transfer speeds. Its rather sad! I’ve been at this for at least 6 months now to no avail!
    any help will be really appreciated

  33. Rockit99 says:

    Well that did it for me and I thought I’d set the USB to ‘3’ already!

    Thanks for the tip!

  34. Bjorn says:

    I also had data transfer problems. Alle Cat6 cable, gigbit switches. Everything checked with testers, I was going crazy.

    Eventually a pro network friend of mine asked: do you have a Sitecom switch in your network? Yes I had one, after replacing it with a proper switch all is extremely stable at 115MB/s.

    Do you have a Sitecom switch? Do the following:
    Disconnect all cabels, place it on the floor with a bit of room around it, then smash it intensively with your foot until only tiny pieces are left, THAT’s my recommendation for Sitecom hardware!

  35. Homer says:

    The instruction above didn’t help. Finally solved for it with these settings:

    Under File Services -> SMB/AFP/NFS
    Max SMB – SMB3
    Min SMB – SMB2
    Encryption – Auto
    Enable opportunistic locking

    Under File Services -> Advanced
    Enable file fast clone
    Enable Windows network discovery to allow file access via SMB

    On Windows 10, turn off SMB 1.0 and turn on SMB Direct

    Hope this helps. Good luck

  36. mulder says:

    No luck on a DS918+ write performance on gigabit LAN between a PC with an SSD can only push files to this NAS in RAID 10 at 20MB/s and read at 50MB/s? I have RAID1 IOMEGA NAS’s from 15 years ago that are faster. SMH. SAD.

    1. Kurt C says:

      same here. changed settings. but problem remains… DS218j

  37. Federico says:

    Thank you! The transfers for DS Photo (Android) are much much faster than before 😀

  38. Tom Mensink says:

    I applied all these settings on both NAS and Windows 10 PC and regretfully this all doesn’t work for me. Not with wifi and neither with direct USB cable.

    However the zip solution works: 250 MB of files in a folder which would take 11 hours with about 50 bits/second, is now copied as .zip file in a few seconds to the NAS!!

    Would still be nice though to get a speed on multiple single files which is about 100.000 times faster. Something must be terribly wrong.

    1. Bob McKay says:

      Hi Tom,

      The speed your seeing above is unfortunately not down to the connection speed of the Synology but purely the admin overhead at source and destination for moving lots of small files. This occurs even on a business network when copying to a high-end Windows server. I used to run a web design company and websites, by definition, are made up of thousands of small files – we used to see the same problem you’re seeing all the time.

    2. Manni says:

      Hello Tom Mensink,

      did you find a solution? I face the same problem.

      I have also very small transfer rates on small files. Also as you, the time needed to copy many small files has a multiplication by a big factor compared to big files. The NAS itself on USB copy and everything else is very fast, also on small files.
      But transfer rates drop high on WLAN even on really, really great WLAN conditions. Transfer rates also only have a high drop on small files, not on big files. Same as you.Big files are transfered great.

      Zipping file is not working in every case. For example using DSM as SVN Server or as Cloud-Synchronization, you want to have also fast transfer rates on small files.

      Do you have a tip?
      Or anyone else who has this problems?

      I tried several settings and googled very much! But no solution. The high drop in transfer rate is only on small files on WLAN (also on 5Ghz with very good condition).

      I tried several DSM Settings, I switched of IP v6, I tried Windows tweaks. But it is still slow on small file over WLAN. As Example, slow is under 100 kbit/sec (30-50 kbit) for small files vs. 80 Mbit/sec on big files. So the difference is very high.

      Copying same small files out of USB to DSM is fast. Copying same small files out LAN to DSM is also relatively fast. Not fast as USB copy or copy on DSM itself, but still at around 5-10 times faster as WLAN.

      I hope someone has a tip.
      E.g. I want to speed up SVN on very big bunch of small files to DSM.

      best regards

      1. Manni says:

        As side note:

        Also the calculating time for deleting a big bunch of small files is incredibly slow over WLAN on DSM.
        On local DSM or local Windows it deletes the files in a blink, it is so fast, that you do not see any popup. And when deleting the same files on DSM over WLAN, you need 20 seconds. Also here, a very, very high factor of needing more time for the same task.

        Thanks a lot for any help!

  39. Nick says:

    I have tried to apply the instruction above on DS918+. Write performance still the same at 5mbps max 🙁

    Is it a must to connect with ethernet cable to transfer file in order to get a faster speed? Or the instructions above can also increase the transfer speed via wifi as most of the members with me are using wifi to read/write file to the NAS.

    Any help would be greatly appreciated.

  40. GaryB says:

    This worked for me.
    I started seeing speeds up the 100Mbs after making the change.

    The other thing I did was copy to the NAS directly through the computer folder on the network, not through the media server. Most certainly do not transfer using Its really slow.

    Sonos Problem.
    I found that after transferring all my music files to my new NAS the sonos failed to sync.
    Seems that Sonos uses SMB1. I had to reset the minimum back to SMB1 .

  41. Stacy says:

    Thanks for this. May have also greatly improved my CloudSync to DropBox syncing.

  42. Dexter says:

    For anyone that still has this issue, keep the above synology settings:
    Maximum SMB protocol = SMB3
    Minimum SMB protocl = SMB2
    Transport encryption Mode = disable (I suggest leaving this at auto, encryption DOES impact speed no matter what OS client you use)
    Enable opportunistic locking = Enable

    What I found out with a Windows 10 O/S:
    Configure the network adapter (I did this with a WIRED connection) -> Advanced settings -> WINS ->NetBIOS setting. ENABLE NetBIOS over TCP/IP.

    That above setting kicked my Synology DS413J from a dismal 8-10MBps to an average 30 – 55MBps. And yes, speeds go quicker if you configure the synology file service to disable encryption.

    1. Bob McKay says:

      Hi Dexter,
      Thanks for this – out of curiosity what Synology model do you have? I’d also be curious to know your setup generally as I’m very surprised that a legacy protocol like NetBIOS would impact your transfer speeds.
      Appreciate the detailed instructions if this is able to help others though!

  43. Nathaniel says:

    This is a productive discussion; thanks to all the contributors.

    Changing the settings did not work for me and I’m getting ~5MB/s with an rsync transfer of a lot of photographs ranging from about 10MB to 50MB in size (hundreds at a time).

    I have a Macbook Air connected to a Time Capsule router (gigabit) through a USB / Ethernet adapter. The USB should be capable of 5Gb/s so I don’t think it is throttling the ethernet (Cat5e cable). DS218+ is connected to Time Capsule as well (Cat5e).

    I would appreciate suggestions!

  44. Julia says:

    Hi all, I have a DS218+ and I’m struggling to upload folders.
    I have my Mac wired to the router. If I do a speedtest on my computer it says 605Mbps DL and 107Mbps UL. When I transfer the files over Synology Drive drag and drop, but also on Finder, is super slow. The speed shown on Synology Drive is 2MB/s.
    I set evrything up as described above, but still very slow, is there anything else I can do?
    Is this transfer speed normal for the internet connection I have?
    Thank you so much for your support

    1. Bob McKay says:

      Hi Julia,
      Lots of unknowns here so a few questions:
      You did a speed test, presumably that is of your network connection not your internet connection? (dam fast if its the latter)
      You ask if the speed is normal for the internet connection you have – I’m assuming the Synology and your MAC are both on your network so the internet speeds shouldn’t play a part.
      What sort of files are you copying?
      My best guess here is that the appropriate protocols aren’t enabled, this guide here shows the settings for AFP, etc. when setting up Time Machine for Mac backing up to a Synology NAS, I’d check out section 1.3 of this guide:
      Hope that helps.

  45. Dani says:

    Hey all! Super helpful thread. I’ve enabled the SMB services and the upload speed has increased dramatically.
    But In my DS218j when using Synology Drive 2.0 from an external location if I try to download a file the upload / download speed is super slow (>1mb). But from the same external location if I access to the DMS vía DDNS ( and I try to download some files from File Station i am getting 20mb/s speeds, something more reasonable. Maybe Synology Drive cannot use the 5001 port and is accesing to the NAS via QuickConnect? Makes sense? How do you do to increase the speed of Synology Drive?

    Thanks in advance!

  46. Patrick says:

    Wow, I’ve read the whole thread here, but nobody seems to get the issue I have. People seems to have speeds issues. I’m in the process of transferring data from my old NAS (Netgear 4 Ultra NAS – RAID 5 – 4 x WD Red 3 Tb) to my new one (Synology DS1817 – SHR-2 4 x 6Tb WD Red). So I’m transferring data over network which is all Gigabit network, and I reach about 420Mbps, I’m pleased with that.

    The issue I’m facing it that about 20-30 after starting a transfer, which is made either from Windows Explorer, Directory Opus built-in transfer dialog or even bvbackup 2, a small but useful backup utility, it starts to be really slow. If I reboot the Synology NAS, it goes fast again, that’s why I think it’s the issue here. But as the transfer foes on, the delay between files transfer (each of them are between 1Gb and 5Gb) becomes more and more important, then, after 20-30 minutes, you can count about 2 minutes between each file transfer, and finally, after 30-40 minutes, the network link on the NAS goes down, the shares drop, I have to reboot the Synology NAS to get it working again.

    Besides that, everything is fine, but it’s like if I ‘hammer’ the NAS by transferring a lot of files into it, it seems to become overwhelmed and the it drops ethernet connections all of sudden.

  47. Albert says:

    Thank you!! It was just sitting there timing out; and now I’m at max speed.

  48. Bobby says:

    Thanks. If my read speed is consistently over 110MB/s but the write speed is stuck on 84-86MB/s what could cause that?

    I tried the above and most of the suggestions in the comments.

    1. Bob McKay says:

      Hi Bobby,
      Writing has a higher admin overhead that reading (due to writing the data, file allocation tables, permissions, etc.) so I would assume this is the cause – still decent speeds to my mind.

      1. Bobby says:

        Thanks for your response. I should have noted that my write speeds would start around 110 and settle around 94-101MB/s.

        Nothing has changed with my network. It’s just a bit of a pain with transferring large files now with the decreased speed.


  49. jeroen says:

    thanks for the exellent info,
    i was frustrated, uploading files to my nas was at 3 kps !!!!! (with a wired lan connection),
    i followed your tips and at first i reached 4mbps which was an extreme improvement, but after a minute everything dropped back to 5 kps

    i was doing everything with quickconnect and this seemed to be the mayor problem,
    from now on i only upload using windows explorer, i have upload speeds of 8MBs to 16 MBs,
    maybe not what its supposed to be but now at least i can do something

  50. WHW says:

    Found this thread while googling the issue.
    Same thing on mine (DS218PLAY). Suddenly I couldn’t get any transfer speeds above 2 – 2,5 MB/sec.

    I was connected through QuickConnect. None of the solutions in this thread seemed to fix it for me, but if I used Explorer and simply navigated to the share, speeds were back to where they were supposed to be.

  51. a7u4 says:

    Worked on DS414j. Thank you

  52. F says:

    Hi experts, I turn to you with these requests. I bought a Synology DS218j NAS server and a Seagate BarraCuda 4TB disk into it. I managed to install everything, get it working, but I copied the files slowly.
    I connect to him so I created a network unit in the pc with his address: and saved the login data. While downloading from it is always about 100 but when writing it is copying 3GB file slowly 10-40 all the time from the same location and when copying 20 and larger file speed is between 114-88. And that’s strange to me. I have no switch to test it with. But when copying from PC 1 to PC 2, the speed is fine around 105 and no matter how big the file is. It’s the same whether I copy from PC1 or PC2.
    When I connected the NAS directly to the PC so nothing changed, just the IP address of the NAS and I had to create a new network unit but that’s understandable. If I have to change and re-set the network adapter on the PC and NAS IP so I do not understand and I did not. I have Samba 1 turned off in windows 10 and set as minimum SMB2 and max SMB3 in NAS. Encryption is on the car, renting SMB2 does not change its on or off. Opportunistic Locking is on, WS-Discovery is also on. I don’t know what to do anymore, so please ask for advice.
    Thank you.

  53. Dan says:

    Omg thank You very much. I am now on 80 MB/s from max 25 MB/s

  54. Jason says:

    I have been experiencing the same problems as many posters here.
    I have slow transfer speed between my DS218+ and 2016 Macbook.
    I have tried all the suggested fixes with no success.

    Wifi Network here has 2 Ubiquiti AP running at 5Ghz connected to Edge routerX through a Netgear switch. All ports indicate a 1G ethernet connection. Laptop Wifi Connection speed ranges from 400mbps to 200mbps.
    Doesn’t seem to matter where I am in the house, Black Magic reports about 22MB/s read and write.

    I’m lost now. Don’t know what to do next. I have SMB as the only protocol on the DS218+
    Max SMB – SMB3
    Min SMB – SMB2
    Transport Encryption – DISABLED
    Opportunistic Locking – Enabled

    The NAS is configured in Hybrid Raid mode (SHR) running 2 WD Red drives (4tb) which are reported as being healthy and only approx 12 months old.

    I’d really appreciate anyones help as I’m about to go nuts. I’ve spend weeks trying to fix this.
    There maybe a nearly new DS218+ on Ebay soon.

    Thanks in advance for any ideas….

    1. Bob McKay says:

      Hi Jason,
      This actually looks about right to be honest. Wifi rarely delivers even close to the listed link speed in terms of throughput (to quote this article: “In addition, net IP layer throughput of WiFi is typically 60% of the air link rate due to WiFi being half-duplex”). Obviously you then need to divide by 8 to get the Bytes per second rather than bits so in your case if we call the average speed 300mbps, 60% of that is 180mbps, divide this by 8 to get the bytes per second gives you 22.5 MBps (note bytes rather than bits).
      The true test of where the bottle neck lies though is to do a speed test with a wired connection.

  55. Jason says:

    Hey Bob. I finally got around to testing a wired connection and was seeing between 90-100MB/s for both read and write. After re-reading your previous comments, I am thinking that wifi and wired connections may be performing as expected?

    I’d really appreciate your thoughts and comments. Thanks acne.

  56. jason says:

    Thanks acne (?) *again* !

    1. Bob McKay says:

      Hey Jason,
      You’re welcome! Autocorrect strikes again huh!? 🙂
      All the best

  57. Jose A. Eiroa says:

    Hi,, it doesn´t work for me.. just 10Mbps..
    Nas conected to router with cat6 wire..Router conected to PLC with cat6 wire..and Pc conected to PLC (3m far from main PLC) with cat6 wire.. I know conected through PLC decreases speed, but … it´s just 10Mbps..
    I think the problem is inside synology ds218.. in network status 100Mbps, full duplex, mtu 1492. Is it right?.. It should be 1Gbps, right?..

    1. Bob McKay says:

      Hi Jose,

      I’d be very surprised if the bottleneck is the NAS, I would guess the PLC (I’ve assumed you mean PowerLine Convertor/Connector). While PowerLine connectors are good, they can get interfernce from lots of sources. A common problem I have seen is from AC/DC adapters (for example laptop chargers, phone chargers), generating ‘noise’. Things I’d try:
      – Plug in directly to the NAS via an ethernet cable and test the speed, if this works you know the problem is the PLC
      – Trying switching off anything not needed and do another test with the PLC, if its faster, slowly turn things on until you find what is generating the interference.

      To be honest, if your PC is only 3 meters from your router, I would use either a network cable or wifi instead of a powerline unit – I only ever use those as a last resort.

  58. Allan Howarth says:

    I did all the steps above and rebooted the Synology NAS, but still getting upload speeds of 10Mb/s.

    1. Bob McKay says:

      Hi Allan,
      If you need help from the group here you’ll need to give a lot more information (how are you connected, what are you copying, what’s the listed speed of your connection, what hardware, etc.)

  59. Dave W says:

    Found this page today and it has completely resolved my slow transfer speed issue. I was contemplating creating a subnet and using a second router as I originally thought it was a routing issue but this simple change has increased my transfer speeds from ~20MBPS to ~110MBPS. Absolutely brilliant – thank you so much! 😀🙏

    1. Bob McKay says:

      Hey Dave,
      Thanks the comment and glad it helped!

  60. Joey says:

    Hey Bob,

    Hope you’re doing fine and thank you for this article which has helped many people!

    I recently bought a DS218 to backup my projects that are really important to me. However, currently its only throttling around 300kbps of download, and 20kbps of upload. After your suggestion its still the same. In the first 5 minutes or so it was around 20mbps, but then it started to drop really fast. At this current pace it will take me 11.5 days and that is not acceptable. Is there any way of fixing this issue before sending it back? I am using a MacBook Pro 2018 running macOS 10.14.6 Mojave. Backing my data via Cloud Station which is connected via IP (192.168.x.x). No other processes are running, CPU is at ~5% and RAM around 15%.

    Hope anyone can help.


    1. Bob McKay says:

      Hi Joey,
      Are these projects website projects by any chance? I only ask because what it sounds like you’re hitting is the administrative overhead of small files (which occurs no matter how you transfer them, even copying to a local disk). If that is the case, there’s a number of ways you could solve this and its about choosing the right one for you but firstly I would recommend using some sort of sync tool rather than doing a full copy each time you want backup a project – a smart sync tool (such as RSync on Linux or RoboCopy on Windows) will copy on the files that have changed, making it perfect for website backups and it can run in the background on a schedule. Other ways you could do this are:
      Store the projects on the NAS and work from there (backing up the NAS to the cloud for CloudSync)
      Backup the files from your PC directly to OneDrive/Dropbox/Google Drive and use CloudSync to download a copy to the Synology
      Zip the projects before you copy them (a zip of the same files will transfer quicker)

      Hope this helps

      1. Joey says:

        Hi Bob,

        Thank you for your reply. The projects are not for websites but for music stuff, so still could hit the administrative overhead of small files probably. 1 folder of 225GB contains 120614 files! I still have slow speeds but ordered a ethernet adapter today. Hopefully that will make a difference. Thanks for your tips!

  61. Lawrence C West says:

    I’ve had a Synology DS416play with 16 TB of disks for nearly 4 years now. I have been unable to use it for backup due to horrible performance. According to Resource Monitor, the transfer rate is only 3-5 kB/s at peak! In two weeks, 1 TB of my laptop data is still not fully transferred. When I use a USB3 disk the full backup is only a couple hours.

    On my old laptop, everything else operating went to a crawl, and the backup never finished after weeks!!!
    On my new HP Zbook with an i9 processor, the CPU is no longer being overloaded, but the backup is still crawling. I have a Gb/s Ethernet wire connection with a Gb/s hub only a few feet between the laptop and Synology.

    I tried all the settings suggested above, without success. Actually I’m stunned people get Mb/s not Kb/s, yet still complain. How does anyone get the Synology backup to work? My previous Windows Home Server worked way better, but no longer supported, unfortunately.

    1. Bob McKay says:

      Hi Lawrence, so that I don’t waste your time telling you things you already know, let me know your experience, etc. A bottle neck that small is definately not going to be processor related, something else is going on. A few questions:
      1) What speeds to you get if you simply copy a large file to and from the NAS (not a backup)
      2) It sounds like you’re doing a full system backup (e.g. whole PC/laptop), is that correct?
      2) What backup software are you using to perform the backup?

  62. Jon says:

    Dude, thank you so much! I’ve been dealing with 6MB/s downloads forever, and I thought it was just a dodgy router.

    I finally resolved to fixing this, and came across your post. I made the changes, and it instantly went up to 45MB/s on small files.


    1. Bob McKay says:

      Hi Jon,
      Glad it helped and thanks for the comment!

  63. diego says:

    BOB, mate….
    I don’t know how to thank you ! I had problems in playing 4k hdr movies, especially the ones with very high bitrate….I couldn’t watch 10 minutes without huge stuttering….I noticed poor transfer speed from/to my NAS (50Mb/sec wit ha gigabit lan)
    Ilost two days tryng to find solutions, cables, switches, router, created NFS shares, do every kind of test…..the n I find your page: now I have 90/100 Mb/sec transfer rate and I can enjoy movies without any problem.
    I just wanted to tell you
    Huge thanks and hug form me !

    1. Bob McKay says:

      Hey Diego,
      You’re very welcome! Thanks for the kind words and I’ll take a hug 😀
      Enjoy the films 🙂

  64. David L says:

    Firstly, thank the lord for this thread… I did a lot of searching for this topic. Great work, Bob – thank you.

    I tried all of these settings, with no luck – until I had a powercut due to a storm yesterday. Once the power came back on… perfect – went from around 4Mbps to 85Mbps. Awesome. The next day – I’m saving a bunch of files to my NAS and suddenly I’m back down to the 4Mbps mark again. Checked all of the settings to make sure I wasn’t going nuts – but was all as it should be.

    So, last thing to try – to protect my sanity was to flick off the power to my powerline. I only flicked off the unit connected to my iMac, out in my garage office for two seconds – and then back on again (didn’t touch the powerline unit at the router). And now I’m back to 85Mbps again.

    Like others have stated – my read speads are fine from the NAS (DS218j) it’s only send TO the NAS which is a problem.

    What the hell is going on with my setup? I mean, I’ve sort of found a really janky workaround for now – but flicking one of my powerline adapters on and off now and then seems like something I should be able to avoid!

    Thanks in advance!


    1. Bob McKay says:

      Hey David,
      This is going to sound a little odd but I would go around and unplug anything in the vicinity of powerline adapters that is electronic (not necessarily electrical, simply electrical devices are fine).
      I say this from experience. Years ago I was staying at a friends house and connecting to wifi in this guest house which was fed from a powerline adapter. It worked great but every now and then, the speed would bomb – I couldn’t work out what it was. After a few days I realised it was whenever I plugged in my second laptop charger (a cheap copy) in to a nearby socket. It caused interference electrical ring main that forced the PowerLine to “step down”.
      Ultimately if you want to know if the problem is in the NAS or your computer, you need a direct cable connection (no powerline, no wifi) and that’ll at least let you rule those out (even if you have a cable trailing through your house for an afternoon).

  65. Sharon says:

    I’m trying to use Hyper Backup to Synology C2 service.
    The best I get from my ISP is 30mbs
    The Synology (DS416) is connected to an unmanaged switch and that in turn is connected to a Powerline plug.
    This other in of the powerline plug is connected to the router.
    The best upload speed i get is 300kps
    I have made the changes in your opening post, but this has made no difference to my speed.

    350 KB/s Upload and 10 KB/s download.
    btw files transfers between PC and the nas are just fine. (PC is connected to the same switch as the NAS)

    At the moment it’s not practical to cart the nas to another area of the house to see what a direct connection to the router would give.

    1. Bob McKay says:

      Hi Sharon,
      I’m afraid you may have to either cart the switch or buy a long network cable. In order to rule out the powerline adapters, I’d highly recommend running a direct cable from the PC to the switch.

  66. Sharon Heritage says:

    I’ve received an update from Synology today.
    Apparently that speed is about right for my 30mb broadband.
    So it would take over a month to upload 300gb
    strangely enough if i drag and drop a backup file from my desktop, it will take just over two hours…..

    In the UK, in the part i live in i could get 50mb but that costs over £50 per month, which is too expensive when your on a limited income. (about 62 dollars)

    1. Bob McKay says:

      Hi Sharon,
      I’d dispute that from Synology to be honest. Have you done a speed test to see what your maximum up/down is:
      30 Mbps should give you 3.75 MBps download speed (notice the uppercase B to signifiy bytes per second, not bits). If you are getting 30 download, I would expect at least 10Mbps upload (which is 1.25 MBps upload) which should upload you3 300gb in about 4 days.
      Hope this helps
      P.S. I’m in the UK too. 🙂

  67. Sharon says:

    My isp is TalkTalk, and because I live in the back of beyond it doesn’t matter which company I use 30mb (download) is what i pay for, and it swings between 15mb to 25mb.
    Just done a speedtest and it reports15Mbps down and 1.97Mbps up.
    This is using a PC connected to an unmanaged switch (gigabit) then into a powerline (gigabit) (wifi turned off) which is picked up by another powerline straight into a Synology router.
    The reason why I’m actually experimenting with this is because my secondary NAS (DS416j) had a disk fault so I’ve turned it off for a few days whilst waiting for a replacement disk to arrive. I’m trying the Synology C2 30 day trial.
    The other solution is to backup the photos as is to Amazon Photos, Microsoft OneDrive, or Flickr Pro. But whilst they are okay for photos, they won’t do versioning (well Microsoft Onedrive sort of does now, but 1 file at a time)
    I was looking for a true set and forget online backup with versioning.
    My other choice is to create Hyper Backups to 2nd NAS and have that Chugging away uploading said back-ups to synology.
    The problem i see with this is NAS A sends weekly backups to NAS B
    NAS B starts uploading this to Synology
    However the following week NAS A again sends a backup to NAS B.
    NAS B is still uploading last weeks backup.

    The final option is to create the backup NAS A to NAS B using hyperbackup.
    Download the Backup file to the PC….then upload THAT file to my Amazon drive, One Drive, ect
    Although individiual file size limitations might come in here. So i might have to create smaller job, maybe one for each year.
    Living in the stick is wonderful, but you pay a price with the internet limitations.
    Maybe USB 3 drive and offsite backup is the way I’ll have to go.

    1. Bob McKay says:

      Hi Sharon,
      Dam, it does sound like you’re stuck there unfortunately. I’m out in the sticks too and we used to only have ADSL (v1) with slower speeds than yours. Given that your connection has a hard (and very low cap) and your uploading data that doesn’t really compress (I’m assuming your image files are already compressed, e.g. JPGs) your kind of stuck. The only other factor here is the volume of data you have changing each day – if its low you could obviously haul your NAS somewhere with faster broadband to do the initial “seed backup”. I actually created a similar setup to yours for a friend who is an avid photographer in a rural rea, she uses Dropbox on her laptop to store her photos from her camera (and auto upload from her mobile phone), when they are uploaded to Dropbox and she’s done editing them, she switches Dropbox to not keep a copy on her laptop (due to storage contraints). No quite seperately, we have configured her NAS on her home network to synchronise ALL of her photos to it, which works ok because the download speed is better (and the photos are uploaded when she is out and about on faster connections generally). This means if she needs quick access to her old photos when at home, she does so via the NAS. Any changes she makes there are synchornised back to Dropbox for a “single version of the truth” for her data but she has a complete local copy, a complete cloud copy and the option to easily do the uploading in other locations.
      Not sure if that would work for you but its good for her.

  68. Hi!
    Thanks to your article I solved another problem: Synology Drive Backup was stuck, it seemed to loop.
    I just changed one settings:
    Advanced Settings: Minimum SMB protocol: from SMB1 to SMB2
    Now the Drive Backup works.
    All Best

  69. smelkin says:

    Well, here’s my go at it.

    I have a brand new 420+ with 3x6TB redwolf drives. I am attempting copy of important files from my Windows 10 laptop to the NAS. I did this by dragging and dropping the folder from My Computer to the NAS file transfer window.

    I am getting speeds of 142 KB/s to 3MB/s. It is bouncing all around. All cabling is CAT6. laptop NIC shows 1GB connection as does NAS port. All connections go through an unmanaged GIGA switch, which incidentally shows giga connections on relevant cable port lights (1000MB vs 100MB lights).

    I was excited to find the settings here and I changed accordingly, but see no difference in speed. I abandoned one attempt yesterday that was still going at 20 hours. It was a 5.2 GB folder of files with many sub folders/structure.

    I also tried this, from Homer above:
    Under File Services -> Advanced
    Enable file fast clone
    Enable Windows network discovery to allow file access via SMB
    On Windows 10, turn off SMB 1.0 and turn on SMB Direct

    I’m at a loss here. Anything else to try?


    1. Bob McKay says:


      If I were you, try and find a single large file (say 1GB upwards) and copy that and see what speed you get. That gives you the true network through put. Lots of smaller files each have an admin overhead (small at the source, larger at the destination) and it can have a big impact. When I copy websites consisting of – for example – 30,000 tiny files amounting to only 100Mb, it takes ages compared to a single file 40 times bigger.

  70. smelkin says:

    Thanks, I will try as soon as the current copy operation (which has been running overnight) is done.

  71. fahad says:

    Hi Bob,
    I tried the steps suggested I even tried other tips on the thread. And I cant just manage to improve or change transfer speed. I get a maximum of 27 Mb/s and drops as low as 16Mb/s then tops again at 27Mb/s and so on(fluctuating).

    Please note that I am using DS 1019+
    Network status: 1000Mbps, full duplex, MTU 1500
    I am connected directly to the NAS through a very short cat7 cable(chaged to cat6a and tried different cables of both in case the cable isnt functioning)

    It seems to me that I am doing everything right and connected direcrly(no router or switch) to the NAS but still cannot get the results I am hoping.

    Your kind advice is much appreciated!


    1. Bob McKay says:

      Hi Fahad,

      What sort of data are you trasferring? Have you tried transferring a single large file (for example 4GB) and seeing what speeds you get versus a bunch of smaller files?

      You mention you’re connected *directly* to the NAS, I assume you mean via a switch or are you using a crossover cable, etc.

      1. fahad says:

        I am only testing to transfer single files sized
        aprox 10 gb To 20 gb
        I tried now transfer single 4gb file and still get same results
        The transfer rate isnt even stable or fluctuating slightly

        Its going down from 27 mb/s to very low as 12 mb/s and so on
        Fluctuating and not stabalizing

        I did everything i could to fix it with no success! I am going crazy!

      2. fahad says:

        I am trying to transfer single files sized 10gb to 15gb i tried now to teansfer single 4 gb and the same problem i am getting

        The speed is not stable as it is sharply fluctuating from 27mb/s to very low as 12 and so on

        I am not using any switch or router just direct cable(all sort of cables cat7 cat6 cat6a)

        I wanted to eliminate all possible bottlenecks but no luck!!

        Its realy driving me crazy!!

        1. Bob McKay says:

          Hey Fahad,
          If you have a direct cable and a large file is maxing out at 27MBps (Bytes per sec) which is equal to 216Mbps (bits per sec) then something is definately wrong. If I were you my next to experiments would be:
          1) Try reading a file from the NAS – do you get the same speed reading from it as writing to it?
          2) Plug two cables from the NAS to your network switch and enable Link Aggregation on the NAS (see here:, then plug the laptop in to the switch and try that.
          3) Try a different laptop to rule out a problem there.
          4) Try plugging in a USB 3.0 drive in to the NAS and copying a file to it from the network (to rule out problems with the harddrive config)

      3. fahad says:

        Do i have to use only crossover cable when connecting my pc to the NAS?

        1. Bob McKay says:

          No if its given you a connection then your NIC has autonegotiated as a crossover.

      4. fahad says:

        Hi again Bob,

        I dont why I cant see the recent replies here in the thread but i got it through the email.

        I tried all 4 steps you suggested.

        First I tried the transfer both ways on the NAS I still get the slow transfer speed from the NAS top today at 20 MB/s and even worse writing to the NAS with a maximum speed of 10 MB/s.

        Second I tried another laptop and still the same.

        Third i tried USB 3.0 and i got xtremly fast transfer and way faster when transfering from the USB of course ruling out any harddrive problems.

        Last I did the aggregation and still very slow transfer but a bit more stable above 20Mb/s.

        Its worth mentioning though that before i tried what i detailed above i got a moment when the NAS started transfering at a very high speed that i never experienced before reaching about 75 Mb/s and started fluctuating above 50.

        I got excited. But when I restarted the NAs and tried again i am back the slow transfer.

        Anymore ideas on what that could be?!!
        Thank you

        1. Bob McKay says:

          Hi Fahad,

          If you got really fast transfer speeds when transferring *from your laptop* to a USB drive stored in the NAS (over the network), then to me that actually points to the hard drives being the problem. If you transerred from the USB port in the NAS directly to the drives in the NAS then yes, that indicates the hard drives are fine.
          Just to check, is the NAS brand new? If so, has the RAID finished building properly because I believe the Synologies have an option of still building the RAID array while allow it to work and this option can take a VERY long time and affects performance.

      5. fahad says:

        No i have tried to transfer any files from the laptop to the USB or the opposite.

        I only did the transfer from the USB on the NAS to the volume and the opposite.

        And im sure the raid has finished and im running on SHR ( 1 disk protection)

      6. fahad says:

        And now i tried to download from the USB to the laptop and i get pretty similar results to what i get usally barely above 20

        1. Bob McKay says:

          Hi Fahad,

          Wow Ok I’m running out of ideas now I’m afraid. At the moment everything is pointing towards a problem with NAS networking. Final suggestions to diagnose the problem:
          1) Try disabling all the applications on the NAS *AND* any firewalls, etc. and disable the firewall on your laptop (and any antivirus). If it works after this, we know its a software issue (good)
          2) If the above doesn’t solve it try installing an FTP server on the NAS and transfer files from the laptop to the NAS using FTP (if this works, it confirms the problem lies with the transfer protocol, e.g. SMB2, SMB3, etc)

          Hope one of these helps!

      7. fahad says:

        Ok i will try first solution for now
        But for the second i have no clue what is ftp server and what role it plays or how to do that as i am not an expert can you please direct me to a link with whole description.

        One last thing if the problem lies with the transfer protocol what doeas that mean? Does that mean that i have a defective unit?

        1. Bob McKay says:

          Hi Fahad,

          Problems with protcol can likely be fixed as its most likely configuration somewhere. FTP is pretty simple and is built in to the NAS, this tutorial should help: It stands for “File Transfer Protocol” and is designed for just that so should be fast. The truth is, I’m running out of ideas right now.

      8. fahad says:

        Hi Bob
        I thought about doing iperf3 test throug my android phone connected to my wifi and i got this
        Connecting to host, port 5201
        [  4] local port 46386 connected to port 5201
        [ ID] Interval           Transfer     Bandwidth
        [  4]   0.00-5.04   sec   165 MBytes   274 Mbits/sec                  
        [  4]   5.04-10.01  sec   148 MBytes   249 Mbits/sec                  
        [  4]  10.01-15.00  sec   141 MBytes   237 Mbits/sec                  
        [  4]  15.00-20.03  sec   161 MBytes   269 Mbits/sec                  
        [  4]  20.03-25.01  sec   155 MBytes   261 Mbits/sec                  
        [  4]  25.01-30.03  sec   162 MBytes   272 Mbits/sec                  
        [  4]  30.03-35.01  sec   156 MBytes   263 Mbits/sec                  
        [  4]  35.01-40.01  sec   162 MBytes   272 Mbits/sec                  
        [  4]  40.01-45.02  sec   142 MBytes   238 Mbits/sec                  
        [  4]  45.02-50.03  sec   154 MBytes   258 Mbits/sec                  
        [  4]  50.03-55.01  sec   158 MBytes   265 Mbits/sec                  
        [  4]  55.01-60.03  sec   158 MBytes   263 Mbits/sec                  
        – – – – – – – – – – – – – – – – – – – – – – – – –
        [ ID] Interval           Transfer     Bandwidth
        [  4]   0.00-60.03  sec  1.82 GBytes   260 Mbits/sec                  sender
        [  4]   0.00-60.03  sec  1.82 GBytes   260 Mbits/sec                  receiver

        iperf Done.

         What does that tell you?

        1. Bob McKay says:

          That you’ve got fast wifi 🙂 The maximum speed your seing seems to be about the same however (250Mbps~ = 31.25MBps).
          Just to check – when you are connecting your laptop via a cable, have you disconnected from the wifi? Sometimes Windows isn’t good at prioritsing the fastest connection and will transfer over a slower wifi even though a fast wired connection is present (certainly seen that myself). I’m afraid I’ve run out of ideas here – I’d recommend raising a case with Synology and listing all the things you’ve tried.

  72. fahad says:

    Hi Bob

    I give up i managed to do last 2 options and no improvement what so ever
    FTP was even slower!!

    1. Bob McKay says:

      Hi Fahad,
      At this stage I’m afraid I think its probably worth arrange a support ticket with Synology! If you get a fix, let us know!

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.