Boosting performance

I'm running SuSE 9.2 on a Proliant DL380, was working fine, only had problems copy and entire tree from one FS to another (it seems to hang). The backup to tape was during 3 hours. The changes made (/boot/grub/menu.lst): * Deleted the "desktop" kernel parameter * Changed the "elevator" kernel parameter from "as" to "cfq" Now, the backups takes 1h 40 min to finish, any comments? Ciro