One of the first questions in choosing a virtual OS for Windows is the level of hardware support required, which divides into two issues.
- Hardware compatibility. There is still a whiff of black magic about hypervisors, and not all hardware or guest operating systems are guaranteed to work. For that reason, hypervisor vendors publish compatibility lists, and those should be checked against existing and proposed hardware when selecting a hypervisor.
- Hardware support. While existing hypervisors run nicely on current x86 processors, both Intel and AMD have announced VM-aware processors that have special features to support virtualization, and some VM operating systems are relying on those.
AMD’s approach is especially interesting, since they’re scrapping the front-side bus that most modern x86 processors use to communicate with I/O and other functions. AMD claims that the front-side bus in a hypervisor machine is a bottleneck that significantly reduces performance. Intel, which is keeping the front-side bus architecture, disagrees.
It will probably be at least a year before VM-aware servers using the new chips will be widely available.