View Full Version : [ubuntu] Gigabit network sometimes 15 MB /s others 85 MB /s

February 7th, 2009, 03:50 AM
Anyone have any ideas on what I can try with my setup? Between the same two machines on my network it's hit or miss as far as what speeds I will see. The size of the files don't matter, they come from the same directory for the most part, no noticeable difference in the actual files.

Sometimes when I transfer it will get a nice 85 MB / sec through the whole file (and sometimes they are 30 GB files) whereas other times it will get 13 - 15 MB / sec tops.

The card on the ubuntu side is a 88E80001 Gigabit card. It's an onboard nic. All my switches are gigabit, netgear and linksys. Between my windows machines it gets a good 50 - 80 MB / sec.

I can't figure it out for the life of me, do you think it's just a flaky card? It never times out or stops working...

Thanks for any and all help!

February 7th, 2009, 06:10 AM
My personal feeling is that nautilus is the problem. Using iperf I get tansfer speed that is expected

iperf -c willy
Client connecting to willy, TCP port 5001
TCP window size: 16.0 KByte (default)
[ 3] local port 56435 connected with port 5001
[ ID] Interval Transfer Bandwidth
[ 3] 0.0-10.0 sec 114 MBytes 95.7 Mbits/sec

The test is run from the command line, whereas using sftp or samba and nautilus the maximum I've seen is 48Mbps

Iperf is available in the repositories.


February 7th, 2009, 06:12 AM
Thanks for the reply! I'm still fairly n00bish to this stuff, I have samba set up for the shares but I think nautilus is installed on the system... is there something specific I should configure? The transfers I refer to are between my ubuntu box and a windows vista machine.

February 7th, 2009, 06:53 AM
Here are my results from iperf, with windows as the server it is getting horrible speeds, but the other way around it's even WORSE with the 16 Mb. Any suggestions?

Microsoft Windows [Version 6.0.6001]
Copyright (c) 2006 Microsoft Corporation. All rights reserved.

C:\Users\Micro\Desktop>iperf -s
Server listening on TCP port 5001
TCP window size: 8.00 KByte (default)
OpenSCManager failed - Access is denied. (0x5)
[164] local port 5001 connected with port 53816
[ ID] Interval Transfer Bandwidth
[164] 0.0-10.1 sec 92.7 MBytes 77.2 Mbits/sec

C:\Users\Micro\Desktop>iperf -c micro-ubuntu
Client connecting to micro-ubuntu, TCP port 5001
TCP window size: 8.00 KByte (default)
[304] local port 61045 connected with port 5001
[ ID] Interval Transfer Bandwidth
[304] 0.0-10.0 sec 19.3 MBytes 16.2 Mbits/sec


June 13th, 2009, 09:01 AM
TCP WINDOWS SIZE IS YOUR ISSUE set both client and server to 16kB and let us know......

June 15th, 2009, 03:18 PM
Thanks for the reply! I figured as much, the problem I am having now is finding a way to adjust the window size in Vista? I have yet to find a site documenting how to do it, I have done it in XP before....

Anyone know for sure? Just a registry change?