Slow SMB transfer from NAS (FreeNAS) to MBP via WiFi

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Slow SMB transfer from NAS (FreeNAS) to MBP via WiFi

I have noticed that this question (or similar) was asked before, but couldn't find the solution; giving it another try.

I have just set up a NAS on my old PC, installed FreeNAS on it. I'm using D-Link DGL-4500 router set to N Mode, 5Ghz, WAP2 Encryption. The NAS and router are on GIG Ethernet connection. MPB connects via WiFi, I check the connection speed in router's admin page, and it states 270-300 mbps for MBP.

I have SMB, AFP and FTP enabled on the NAS. I can connect to the NAS via WiFi from MPB just fine, and see the AFP and SMB shares in Finder.

Problem: when I try to copy a file from the NAS to my MBP desktop using Finder, the transfer speed is very slow and inconsistent. Keeps jumping from 500 kbps to 8 mbps and back -- very very slow (I get faster speed downloading from internet via WiFi, consistent 10mbps). Now, when I transfer the same file from MBP to NAS (same way, via Finder) then the speed is fast (50 mbps - 60 mbps). When I try AFP, same issue during NAS to MBP transfer, but not the other direction. When I try the FTP, I can download the same file, from the same share, at about 80 mbps, over same WiFi. When I hardwire my MBP to the router on a GIG port then the SMB and AFP transfer FAST both way (about 400mbps).

I'm completely stumped. This does not look like NAS issue, since I'm able to get great speeds in both directions via FTP over WiFi or over GIG Ethernet. The issue only arises when I try to "download" the file from NAS via WiFi over SMB or AFP (when "uploading" to NAS the speed is good).

I've tried to disable IPV6, didn't work, tried different MTU settings on NAS and MBP, to no avail.

Any help would be appreciated.

Thanks a lot!

MacBook Pro 15" C2D, Mac OS X (10.5.7)

Posted on Jun 15, 2009 11:43 PM

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Answer 1

dmitripr Author

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Jun 16, 2009 8:07 PM in response to dmitripr

Ok, I think I've figured out the solution, to a large extent.

Apparently there is an attribute for SMB protocol that controls send buffer size and receive buffer size, on the server. On FreeNAS that is set to 16384 as default for both. I've upped it by 10x to 163840 for both, and looks like that solved the speed issue for "downloading" from NAS. Now my speed over WiFi for NAS to MBP transfer is peaking at 130mbps, and around 100mbps for "upload".

But one thing it did not solve is the consistency of the speed, while "upload" to NAS stayed rather consistent (around 80-100), the "download" transfer jumps A LOT, I'm talking a range of 500 kbps to 130 mbps, and everywhere in between. Seems to be completely random, it will sustain ~100 for some time, but at times will drop to 500 kbps, jump around for some time and then go back up to peak. Just plain random.

But at least I can now transfer 200MB file in about 15 seconds or so, on average, over WiFi.

Hoping the SMB consistency will be improved in the next OS release, but then again, I heard people were hoping for that for the past year or so. We'll see.

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Answer 2

Jul 9, 2009 9:03 PM in response to dmitripr

Had the same problem with an iBook G4 over WIFI.
In FreeNAS on the SMB config page there is a note at the bottom:

Note:
To increase CIFS performance try the following:
Enable 'Large read/write' switch
Enable 'Tuning' switch
Increase MTU

Enabling Tuning made a difference in my case for both AFP and SMB.

Thank you for directing me to the right direction. In my setup, FreeNAS runs on top of Vmware ESXi so you saved me a lot of work trouble shooting this.

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