We showed you in a previous tip how to increase performance with USB drives in Vista by enabling write caching. By default this option isn't turned on because of the "removable" nature of these devices, so you could lose data if you pull out too quickly (the drive that is... ).
Internal SATA hard drives are alot more "permanent" than USB drives, but Windows Vista does not enable advanced write caching by default. You can increase performance of your hard drives by implementing a little-known feature. You could potentially lose data in a power outage, so either use a UPS or enable advanced write caching at your own risk.