On Sat, 2010-02-20 at 02:41 +0100, Kenni Lund wrote: > 2010/2/18 compdoc <compdoc at hotrodpc.com>: > > I would also just use the e1000 emulation. Theres nothing > > better about the virtio devices... > > ...other than lower CPU utilization and higher throughout? Since these > are CentOS/RHEL guests, I wouldn't even consider using e1000, I would > just go for virtio_net. > > I don't have any links, but some time ago there were some benchmarks > (on the KVM development list?), showing the e1000 maxing out at around > 300-400mbit/s while the virtio got around 900mbit/s. Even with the > much higher throughput, the virtio_net driver still had the same or > lower CPU utilization. > > Do your own testing if in doubt. > > Best Regards > Kenni Lund Are you using test-signed drivers or do you have a redistributable source for release-signed drivers (that chain to a microsoft root)? Of course, things are much simpler if you are using 32-bit M$ guests. Never got the chance to test relative performance of e1000 vs the netkvm drivers on a M$ guest, but on a centos5 guest, virtio absolutely blows the doors off e1000 performance. Using ttcp in both directions, typical C5-host-to-C5-guests for e1000 was in the 30-60MB/s range and virtio was in the 300-400MB/s range. Steve