I did some benchmarking mainly with tbench and found virtio better with big packages/maximum throughput and e1000 better with small packages/latency. vhost-net improves virtio quite a lot and makes it superior to the emulated devices. If network performance is a real issue, DMAR/IOMMU gives you direct access to dedicated network devices with nearly 100% native throughput and latency. Best regards, Sebastian On Thu, Jul 22, 2010 at 04:13:29PM -0400, Balachandar wrote: > I can see that virtio network performance is poorer than emaulated > e1000 nic. I did some simple ping test and with emulated e1000 the > average rtt is around 600 microsec. With virtio the average rtt is 800 > microsec. I am using a tap + bridge configuration. I run kvm as > follows > > kvm -m 512 -hda vdisk.img \ > -net nic,model=virtio \ > -net tap,ifname=tap0,script=qemu-ifup,downscript=no > > I am running Debian squeeze distribution with guest and host kernel 2.6.34. > > Does anyone else see some results like this or is it only me? Could > changing the distribution help as i am running a testing one? > > Thanks, > Bala -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
