Ask Slashdot:Performance Testing

Bart Grantham writes "I'm an intermediate (closer to beginner than advanced) Linux user and I'm wondering where I can find more information about pumping up performance. Specifically, when running XFree86 on two completely different SCSI based systems, disk access significantly decreases interface responsiveness. I can understand this to a degree, but the mouse will consistently hang for a second at a time or more. Under Win95, disk access is much faster for nearly any kind of transfer. Is there a repository of information about tweaking Linux for performance (UI or otherwise)? "