I have an 18 month old Dell w/a P4 2ghz (512 L2)/socket 478 w/Rambus memory. Rather than hemmorage $$$ to buy 512mb of PC800 Rambus, I'm thinking about buying a new mobo w/the appropriate flavor of DDR memory. Anyone know the what the best board/memory speed combo will work for my P4 chip w/400mhz FSB? Thank you in advance for your help.