7/Vista has advanced disk options for increasing disks performance. These options are switched off by default. You must switch on the options if you want to get max disks performance. How to do this:
Open Device Manager: Press Window+Pause/Break buttons and click on Device Manager point.
Expand the Disk drives section and mouse double click on the drive you want to configure. In the popped up window go to Policies, Check both the Enable write caching on the disk and the Enable advanced performance boxes and press Apply button.