Gigabit Ethernet

For several months I own a Netgear GS105 Gigabit Ethernet Switch. Today I finally tested performance on my LAN using NetIO.
I own three Gigabit Ethernet NICs: mchammer.arved.de has a builtin 3Com 3C940 (supported by the FreeBSD sk(4) driver), sauna has an Intel 82540EM (supported by the FreeBSD em(4) driver) and jim.arved.de has an RTL8169 supported by the FreeBSD re(4) driver.
The goal of the test was to find out if it makes sense to exchange the NICs between jim (my server) and sauna (my i386-workstation). I suspected the Realtek card having the worst performance.
Here are the results:

jim <-> mchammer 211,5MBit/s
jim <-> sauna 211,5MBit/s
mchammer <-> sauna 319.4 MBit/s

Both tests involving jim had the same result, so i redid the test and found out that the limit is most likely not the NIC but the CPU (a 600Mhz EPIA) which was used 100% during the test.
So changing NICs is not useful, but instead i should consider buying a 1Ghz EPIA System, if i need more performance.