On Monday 31 January 2005 1:49 am, Hans du Plooy wrote:

Hi everybody,

I have noticed that on my workstation (P-III 1ghz, 512mb, Intel chipset, 100mbit 3com network), I can copy stuff over the network at about 8-9mb/s at the best of times. When I do this, my CPU usage is quite high.

I notice the same thing on my home PC (2ghz Athlon, 384mb, Via chipset, SMC network card - tulip driver). On both these machines the CPU load seems to be directly proportional to the transfer rate on the network interface.

I can only assume that his is because both these cards do a lot of the hard work in software, in the driver. Can anyone confirm/deny/explain this?

Either ways, our office would be migrating to a gigabit network soon, and I'm tasked with finding good network cards. Can anyone recommend a gigabit network chipset that fully implemented in hardware - i.e. the network card itself does all the heavy lifting. I'm looking for someting that would affect the CPU usage as little as possible.

Thank you -- Hans du Plooy

One troubleshooting step to do is set the duplex/speed (full/100) instead of leaving it at auto detect on both the NIC and the ethernet switch. You may have to play with the settings depending on the NIC and switch; some like auto-detect and run reliably at full/100 while some need to be hard-coded at full/100 to eliminate too frequent auto-negotiation. This is very hardware manufacturer independent too; they all behave poorly when auto-detect is used. Don't rely on what boot messages tell you either because they don't give the full story of what is happening right now between the NIC and switch. Somewhere in the kernel directories is information on the settings for most NICs that you can apply in Yast/Network Devices/NICs to dictate duplex/speed. Can't remember right now where. Must be age. I know its in the list archives. Stan