Quote Originally Posted by phoronix View Post
Phoronix: KVM Virtualization Performance With Linux 2.6.31

Earlier this month at the Red Hat Summit where Red Hat Enterprise Linux 5.4 was released with support for the Kernel-based Virtual Machine. At this Red Hat event, virtualization -- particularly KVM -- and cloud computing were the most talked about topics. But how is KVM performing these days? With new virtualization refinements going into almost every new Linux kernel release, we have published a new set of KVM benchmarks using the Linux 2.6.31 kernel, to provide updated numbers against our KVM benchmarks from last year and our Core i7 virtualization numbers. This time around, we are also using a Phenom II processor for testing out the AMD-V technology.

http://www.phoronix.com/vr.php?view=14201
Would it be possible for you to test RHEL 5.4, so its possible to compare the two ? (the talk from redhat mentions the disk i/o as one of the key aspects they're trying to improve - and some changes have already made it into 5.4.)