For those curious whether the forthcoming Oracle VirtualBox 4.2 virtualization platform delivers on any performance enhancements, at least as it pertains to Linux virtualization, here are some quick benchmarks.
The problem with VirtualBox is that the graphics performance is very bad. It seems like the screen can only be redrawn at 10fps or something and so the experience is very choppy. I have been using VB for a few years, on different computers, and this situation hasn't improved one bit and is not dependent on the host platform.
The interesting thing is that graphics benchmarks make it look like it actually has decent performance, but somehow the screen isn't updated at the same frame rate so, even if glxgears says it's outputting 500fps it still looks like 5-10fps. I don't get it.
I haven't ever seen Devius' problem that I can recall.. but I do wish VirtualBox would step up their performance somehow. These numbers compared against bare metal were just depressing.. and can we get GPU passthrough support? I don't care if the host has to switch to purely software rendering to do it..
GPU passthrough means giving complete access to the GPU to the VM, so the host must use another GPU (if available) or become headless, not even software rendering. So unless you do have a second GPU I don't think this is what you really want.