Use the SysKonnect sk98lin driver (SysKonnect SK-98xx Gigabit). Depending on your distribution, you may already have “SysKonnect SK-98xx Gigabit” as a NIC option. I have the same motherboard loaded with Fedora and just selected the SK-98 from the NIC list. I also manually loaded the drivers on a different motherboard following the SysKonnect instructions.
The driver can be found several pages in at
http://www.syskonnect.com/syskonnect...02_driver.html
Use the “Open Source Linux” driver as a module for kernel 2.4.13 and above (install-624.tar.bz2). It takes about 10 minutes to install.
You can read a lot about these drivers by searching this forum for “3C940" or “3C2000".