Conclusions
As we have seen, virtualization technology brings with it a lot of convenience, but also a pretty heavy performance penalty. Based on my experience with Virtual PC I would say that Virtual Server does not seem to have made significant performance improvements over Virtual PC. However, for many IT consolidation projects the performance penalty could be acceptable. Many older IT applications run on slower hardware and are not used heavily, and so Virtual Server will be a perfect fit.
However, for your mission critical apps, you will certainly want to stick to “real” rather than virtual servers. The performance penalty we saw here may not be permanent, however, as upcoming built-in virtualization technologies in the next major Intel architecture (codenamed “Conroe”) could accelerate virtualized applications. In the mean time, you will want to run Virtual Server on a reasonably fast server to negate the performance degradation.