Recently got me a Compaq Evo 510 small form factor system
Kona I'm currently running a 1993 Compaq D-510 EPC SFF, 2.4Ghz with 1Gb of DDR Ram. I bypassed the on-board sound card and instead utilizing the Sound Blaster Audigy2 external USB instead.
Two things I found useful in speeding it up was;
A. I'm running XP Pro sp2
B. Tune-up Utilities. The Registry Cleaner and Optomizers are priceless no only for system performance but for maximum Internet Connection as well.
Because the on-board video card is not upgradeable I cannot migrate to Vista (oh well), but aside from that my system has performed flawlessly since '93.
Check the Compaq / Dell site for the BIOS update and make sure that all of your on-boards (NIC, SoundCard and Video) has the latest drivers as well.
Good luck, I do hope all works well for you.
Cp