Project VRC: Clock drift and test results
Project Virtual Reality Check finally posted a new document about previous results and possible clock drift when using the “Login Virtual Session Indexer (VSI)”. Previous test setups and results didn’t take into account how different hypervisors handle passing time.
In my opinion this is a serious setback to Project VRC which is considered an institute in the virtualization world. People will start questioning the results when no new tests will be performed.
Below is a description from the Project VRC website explaining the new whitepaper they published on September 14th 2009. This is a must read for people that already did some testing as well as new tests. In short: ‘Because of Windows clock behavior in virtual machines the results were affected and some hypervisors may come out better than they really are.
This whitepaper is a review and reflection on previous Project VRC publications, the benchmark: “Login Virtual Session Indexer (VSI)” and Windows clock behavior within virtual machines. This discussion is fueled by the fact that results from the individual Project VRC whitepapers are set side-by-side to compare hypervisors. Project VRC has been in discussion with both vendors and community, and performed additional research in this context. Before Project VRC can publish new results, it is important to address any questions, review the impact of this discussion and improve VSI where possible.
You can download it at www.projectvrc.nl
The major conclusions in this Whitepaper are:

