On Sat, 2010-02-20 at 02:41 +0100, Kenni Lund wrote:
2010/2/18 compdoc compdoc@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