[nzlug] Network speed

[Andrew Farago]

Hi guys,
The scenario is the next
Two Linux PC with Gigabit NICs, connected with Cat 6 cables.
The maximum throughput what I could measure was 0.55 Gbps. (Download  
or upload but I never did the two tests in the same time, that maybe  
less.)
If I made it a little more complicated...
LinuxPC}-------{switch}------{BSD firewall}------{switch}------{LinuxPC
Gigabit NICs and Gigabit switches everywhere (not cheap ones)  
connected with Cat6 cables.
A few simple rules and NAT on the firewall.
The max speed what I got was 0.35 Gbps.
I am very-very disappointed. I expected much more. :-(
Is it a week performance or this is the performance of a "Gigabit"  
network?
Do you have any experience?

The computers in the tests had 3Ghz P4 processors + 512Mb RAM.
The test program was the netperf+netserver duo and I performed a  
TCP_STREAM test.

Andrew