This question is really just a port of a similar question on Stack Overflow:
The emerging consensus from that question is that Linux has superior caching to Windows but the specific reasons why have not been pinned down. Does anybody here have any greater insight into the technical explanation?
A few people, myself included, have also noticed that Windows can actually perform better in a VM on top of Linux than it does on the raw iron (native hardware). Why would having Linux host Windows as a client OS increase the Windows performance?