I have this motherboard: http://www.asus.com/Motherboards/Intel_Socket_775/P5GZMX/ and 3 spare CPUS. All of them have a 800mhz FSB but here's their description. P4 631 3.00 ghz/2M/800 SL9KG P4 651 3.40 ghz/2M/800 SL9KE P4 Quad Dual-core 2.00 ghz/1M/800 E2180 I know that by logic the 3.4 is over the 3.0 but if on this setup the 3.4 is overkill I'll just dump in the 3.0. This will be used with an IDE combo of Maxtor 200 gigs and a DVD-RW IDE. 2 gigs ddr2 Onboard 224megs video HTPC, old games, youtube, surfing the net Also: What's better usually? A 2.00 ghz 1M cache or a 3.** gigs 2M cache ??? Thx and it will help on later with my project log.