Actually, I was mainly hoping to verify that it was, indeed, a hardware problem.  One person (Trevor) reporting similar results has fairly decent-quality GigE NICs on both sides – or at least what I *assumed* to be fairly decent-quality NICs!

In your case, I’d say yes, it’s time to test different NICs.  Obviously one of your NICs is OK – although I wouldn’t want to put much money on which one until I tested thoroughly.

I’d also not be willing to put money on whether it’s the NIC hardware or the software (i.e. device driver) – even though you tested under two OSes, the Linux drivers and the Windows drivers share a lot of code for both Intel and Realtek NICs nowadays.

-Adam Thompson

 <athompso@athompso.net>

 (204) 291-7950

From: roundtable-bounces@muug.mb.ca [mailto:roundtable-bounces@muug.mb.ca] On Behalf Of Kevin McGregor
Sent: Tuesday, April 06, 2010 18:37
To: Continuation of Round Table discussion
Subject: Re: [RndTbl] Network performance tuning

[...]
The source hardware seems to be having a problem sending. Receiving, less so:

[...]

...Although push the bandwidth (UDP) too high, and a lot of packets get lost.
[...]
Any further thoughts?