This is a very interesting comparision of virtualization technologies by the Information Sciences Institute at the University of Indiana. It is the most current and comprehensive comparison and analysis of virtualization technologies online.

The paper is from the proceedings of the IEEE CLoud 2014 and mainly looks at use of GPU pass through for scientific workloads. Since GPU workloads are by far the most intensive and exercise most components of the system from cpu to memory and storage throughput we can draw pretty accurate conclusions of general performance of the technologies tested.

There are not a lot of virtualization benchmarks online, the half way decent one was done by Phoronix back in 2013 comparing KVM and Xen, and that didn't look at LXC. This is one of the more credible scientific studies carried out.

As the benchmarks conclude LXC is pretty fast, nearly the same as bare-metal as one would guess. The other interesting thing to note is Virtualization has also come along and both KVM and Xen are very close to bare-metal performance. Xen does face some hiccups in the second set of tests but the authors put this down to some configuration issues.

The paper shows low overhead GPU passthrough is achievable across 4 major hypervisors and two processor microarchitectures. It compare the performance of two generations of NVIDIA GPUs within the Xen, VMWare ESXi, and KVM hypervisors, and also compare the performance to that of Linux Containers (LXC). The results show GPU passthrough to KVM achieves 98–100% of the base system’s performance across two architectures, while Xen and VMWare achieve 96–99% of the base systems performance. LXC is at near bare-metal performance.

For users this is windfall of riches on virtualization technology choices. LXC gives you near bare-metal performance, excellent portability, ease of use and efficiency. For use cases that call for full blown virtualization KVM and Xen offer choice and fantastic performance.