Case1:
Tools: SPECvirt_sc2010
http://www.spec.org/virt_sc2010/results/specvirt_sc2010_perf.html
Sames HW, ESXi 4.1 scores 3824 with 234 VMs, KVM 4603 and host 282 VMs, which is 20% higher.
Case2:
Tools: SPECvirt_sc2010
http://www.spec.org/virt_sc2010/results/specvirt_sc2010_perf.html
3894 vs 3723, KVM 4.5% higher.
Case3:
Tools: SPECvirt_sc2013 (New tools, as of 9/24/2014 only the below data avaiable)
http://www.spec.org/cgi-bin/osgresults
RHEL7 1614 with 90 VMs on a E5-2699v3 platform, which is much higher than last generation E5-2697v2 with 935 and 50VMs.
KVM is clearly better on the performance side, and also the price side.
Case2:
Tools: SPECvirt_sc2010
http://www.spec.org/virt_sc2010/results/specvirt_sc2010_perf.html
3894 vs 3723, KVM 4.5% higher.
Case3:
Tools: SPECvirt_sc2013 (New tools, as of 9/24/2014 only the below data avaiable)
http://www.spec.org/cgi-bin/osgresults
RHEL7 1614 with 90 VMs on a E5-2699v3 platform, which is much higher than last generation E5-2697v2 with 935 and 50VMs.
KVM is clearly better on the performance side, and also the price side.
