[wellylug] Nforce4 motherboard and underperforming network

[David Harrison]

Jamie Dobbs wrote:
> Bruce Hoult wrote:
>> On 5/5/07, Jamie Dobbs <jamie.dobbs at ihug.co.nz> wrote:
>>> I have noticed that my Gigabit ethernet runs about half as fast under
>>> Ubuntu  (approx. 1.5MB/s) using the forcedeth driver as it does in
>>> Windows using the Nvidia driver (approx 3.1MB/s). These figures are 
>>> at a
>>> known network state copying the same files to and from the same 
>>> location.
>>> Is there anything I can do to tweak the forcedeth driver or am I 
>>> best to
>>> just give up and buy a better supported Gigabit card for using under
>>> Ubuntu? 
> It turns out that the monitoring I was using appears to have been 
> scaling it's output.
> The real issue here now appears to be that if I use FTP I get 
> something in the 30MB-40MB+/s mark but if using either Samba or NFS I 
> get around half this speed.
> I've tried tuning the block size for NFS but this has made little to 
> no difference, I'd like to get the performance on par with that of FTP 
> but if I cannot I will just use FTP I guess.

The SMB and NFS protocols will always be a lot slower than FTP because 
of the increased overheads of each.
NFS is faster than SMB but SMB's performance can be improved by turning 
off all logging, see this thread for details:

http://lists.samba.org/archive/samba/2007-March/130440.html

However ignore the bit in this thread about setting Samba socket 
options. This is an old school method of improving Samba performance. If 
you are using a relatively new kernel it does a much better job of 
socket detection. Jeremy Alison posted this bit of info on the Samba 
list so no matter what you may read to the contrary I think he knows 
these things best.


Even with lots of tweaking the best performance boost you can give 
gigabit is at the hardware level. A dedicated gigabit card from a 
respected manufacturer (like Intel) will generally perform much faster 
than an integrated NIC or low-end, no name brand. I would be especially 
wary of the NVidia chipsets as I have had performance issues with both 
the NFORCE3 and NFORCE4 chipsets. They seem to work but don't expect 
them to work well (you get what you pay for).


David