Its interesting that people seem to think that Vista under performs in every area of the system which is quite an incorrect perception. In this demo I show how Vista outperforms Windows XP and I show the under the covers process traces of just how it achieves it.
Demo environment consists of two images. One Vista SP1 and the other Windows XP SP2 both on the same HDD IO and communicating across my home wireless network to a Windows Server 2008 box on my main LAN. Once the two images get going latency gets introduced and things start to slow down….except Vista doesn’t slow down :). Watch and see!

Check out the screencast here

Source- MS Technet