Intel Haswell Linux Virtualization: KVM vs. Xen vs. VirtualBox

The latest chapter to our lengthy Intel Haswell on Linux saga is virtualization benchmarks. From Fedora 19 with the very latest software components for Linux virtualization, the performance of KVM, Xen, and VirtualBox were benchmarked from the Intel Core i7 4770K "Haswell" CPU.

Since last month's Haswell launch we have published many benchmarks of the new Intel CPUs but not being covered at Phoronix until today is the Linux virtualization performance for Haswell. With Intel hardware virtualization enabled, KVM, Xen, and VirtualBox were compared from a clean Fedora 19 64-bit installation.

Fedora 19 presently has the Linux 3.9.8 kernel with GCC 4.8.1, Mesa 9.2.0-devel, and an EXT4 file-system. All of the virtualization components were obtained from the Fedora 19 repository, including QEMU 1.4.2, Xen 4.2.2, and the libvirt / virt-manager components. Xen and KVM virtualization were setup through virt-manager. VirtualBox 4.2.16 was obtained from VirtualBox.org and installed on Fedora 19.

The Intel Core i7 4770K system had 16GB of RAM and a 240GB OCZ Vertex 3 SSD. During testing, each VM had access to all eight logical cores (four physical cores + Hyper Threading), access to 12GB of the system's 16GB of RAM, and a 16GB virtual disk.

The KVM, Xen, and VirtualBox performance from Fedora 19 Linux 3.9 with the Intel Core i7 "Haswell" processor were also compared to the "bare metal" results when the benchmarks were running on the host without any form of virtualization or other means of abstraction. VMware's products weren't benchmarked in this article since their EULA restricts public benchmarking (though VMware has been okay with us running such benchmarks in the past) and their trial software being limited to running on four CPU cores, but a separate article will look at the Xen/KVM/VMware performance on other hardware in the future.

All of this Linux virtualization benchmarking was handled in a fully automated and reproducible manner using the open-source Phoronix Test Suite software and hosting by OpenBenchmarking.org. With using a virtual disk and with Xen/KVM not having a reliable means of shared 3D access to the host's driver/GPU, most of the benchmarks within this article are computational focused to look at the performance overhead for the different Linux virtualization methods.