I setup KVM following the guide here:

http://www.cyberciti.biz/faq/centos-rhel-linux-kvm-virtulization-tutorial/

I setup a bridged network and it worked fine except that the transfer speed is 200KB/s instead of the gigabit speed that I get on the host machine by itself.

I tried editing the guest network settings to set "model=virtio"

http://wiki.libvirt.org/page/Virtio

but this just moves ifconfig-eth0 to ifconfig-eth0.bak in the VM and networking doesn't work at all. I tried moving ifconfig-eth0 back and starting up eth0, which works, but now the transfer speed is ~ 60KB/s

I have no idea what else to try. Any suggestions would be greatly appreciated.