Results of using Jumbo Frames

Duke · 14 Mar 2011 at 18:28

I had a fiddle with using jumbo frames on my gigabit network, to try and speed up transferring data from my NAS. I read up a bit about it and gather it lowers cpu overhead, so can help with NAS devices especially.

Results below transferring a 1.6GB file from the NAS to my desktop (Win 7):

1500 MTU - 22-23MB/sec (default)

4000 MTU - 34-35MB/sec

9000 MTU - 39-40MB/sec

Pretty good result and worth doing if your kit supports it.

http://www.maximumpc.com/article/howtos/how_enable_jumbo_frames

ecksmen · 14 Mar 2011 at 19:47

You've got issues somewhere, you don't need jumbo to hit 40MB/sec. I can transfer on my network (which I consider to be rubbish) at 60MB/Sec from desktop to file share without jumbo frames.

Duke · 14 Mar 2011 at 19:49

Is that to a NAS? PC to PC is much quicker than this.

KIA · 14 Mar 2011 at 20:23

@Duke - using a cheapo NAS?

Duke · 14 Mar 2011 at 20:50

Synology 207+

Skidilliplop · 16 Mar 2011 at 14:49

ecksmen said:
You've got issues somewhere, you don't need jumbo to hit 40MB/sec. I can transfer on my network (which I consider to be rubbish) at 60MB/Sec from desktop to file share without jumbo frames.

That wasn't the idea behind the experiment.
It was to demonstrate the performance difference caused by sending less frames resulting in less processing of headers and less bandwidth cluttered up by headers.
If you get 60MB/s normally you could probably get more with jumbo frames.
And it was conclusive to my eyes. Even in a small home network scenario there are noticeable benefits to it. - Cheers for the post Duke, I look forward to reading the white paper

welshdragon · 25 May 2011 at 18:20

Ive just changed the mtu from 0 to 1500 on my virgin media superhub, the hgihest it will support. Going from 0 to 1500 should in theory then speed up access to my ds210j?

GaryH-21 · 25 May 2011 at 19:06

welshdragon said:
Ive just changed the mtu from 0 to 1500 on my virgin media superhub, the hgihest it will support. Going from 0 to 1500 should in theory then speed up access to my ds210j?

Hmm, I think being set to '0' will either be automatic, unlimited, maximum or something along those lines! So you may or may not see a difference

welshdragon · 25 May 2011 at 20:54

I see. should I change the mtu on my ds210j instead allowing it to push stuff out faster? I assume my htpc will thne connect at the highest speed it can do thus maxmising thruput? I understand changing the mtu on my router should not impact the nas pushing through the switch to the htpc?

Skidilliplop · 26 May 2011 at 12:45

You need the MTU to be higher at both ends, you also need your switchgear in between to support jumbo frames as big or bigger than the MTU you set. Most switches that do support jumbo support up to 9000. some fo the enterprise DLinks i've rolled out support 10k though I'm yet to find a NIC I can set to match that.