Vista Performs As Fast As XP on Same Hardware
The guys at CNet tried to run Vista and XP on 2 computers with identical hardware to see which one would perform better. Surprisingly, the Vista installation was as fast as the XP one.
We loaded Windows Vista beta 2 (build 5384) and Windows XP Professional SP2 on a 3.2GHz Pentium 4, with 1GB of DDR2 memory running at 664MHz and an ATI Radeon X850 XT graphics card. We ran a few of CNET Labs' home-brewed tests on the two operating systems to see if we could discern any significant performance differences between XP and Vista. The results were surprising.
Hmmm, maybe not that surprising considering the specs of the systems they used. They should have tried with lower-end computers instead. I'm pretty sure that if they would have done so, the results would have been very different.