Ubuntu 12.04 LTS KVM Virtualization Battles 8.04.4, 10.04.4 LTS
The computationally-intense Himeno result did improve with Ubuntu 12.04 LTS and when Ubuntu 12.04 LTS was being virtualized.
KVM seems to have slightly greater overhead when running the 7-Zip compression test with its performance dropping greater than in the previous Ubuntu releases that were tested.
Ubuntu 12.04 LTS is trying to edge higher with John The Ripper.