While there are many results to go through, a few items stuck out:
- VirtualBox 4.1 on Ubuntu 12.04 when running on the Intel Core i7 3960X "Sandy Bridge Extreme" performed very poorly. VirtualBox was most often running at a small fraction of the speed of the KVM and Xen virtualization methods for the i7-3960X. VirtualBox on the AMD FX-8150 performed much closer to where KVM was running, but still was noticeably behind the popular Kernel-based Virtual Machine. There is some major issue going on with the $1000 USD Intel processor and VirtualBox, possibly similar to the Xen performance issues encountered last year. VirtualBox seemed to do the worst on Intel with multi-threaded workloads.
- Xen 4.1 generally performed in line with KVM's performance on Ubuntu 12.04 LTS x86_64 with the Linux 3.2 kernel. This is at least for the Sandy-E system, but Xen issues with the ASUS motherboard prevented Bulldozer Xen results from making it out there.
- Between Intel's Sandy Bridge and AMD's Bulldozer for KVM virtualization, the relative performance was generally quite close between these competing latest-generation architectures. If looking at the harmonic mean of the over three dozen tests that were run, the Intel Core i7 3960X was running at 93% the speed of bare metal with KVM while the AMD FX-8150 came in at 90% the speed of the bare metal Bulldozer. Alternatively, with the geometric mean of all the results, the i7-3960X was at 85% the speed of bare metal while the AMD FX-8150 was at 88%. VirtualBox on the FX-8150 was at 85% while the problematic VirtualBox-on-Sandy-E was at 59%. Xen on Sandy-E came in at 94%.
As a bonus (and as I was running some extra tests for Canonical), here are some Clarkfield KVM/Xen/VirtualBox virtualization results from a very different system. VirtualBox on this older Intel Core i7 did have some troubling spots too, but overall was at least better than its performance on the i7-3960X Sandy Bridge Extreme.