The Windows Performance Tools Kit is now shipping along with Windows SDK for Windows Server 2008 and .NET Framework 3.5. A mouthful both, to be sure, but if you use either regularly it won't be long before they become just "xperf" and "the SDK".

The tools are a great help to analyze performance, especially for the trickier cases when I/O might be bottlenecked or lock contention might be involved (and I'm sure many other scenarios, although those are the once I have been involved in).

Congrats to the Windows SDK team!