We all know its too early to compare performance of a developer preview build OS to a matured OS. Still, Windows 8 Developer Preview build beats in almost every speedtest lifehacker did in comparison with Windows 7. Boot time is a significant area where Windows 8 preview leaves Windows 7 in dust. Just look at the results below,
Microsoft still has lots of time to juice more performance out of Windows 8. Lets see how it plays out.
More details on comparison over at Lifehacker.