I'm thinking of buying a Dell workstation with a Core 2 Duo CPU (which has a 1066MHz FSB). However, the company only offers NECC DDR2 533MHz RAM to go with it, but not NECC DDR2 667MHz RAM. The alternative is ECC DDR2 667MHz RAM. Since I'll only be running trading and charting client software, not using the PC as a server, it seems clear that ECC RAM isn't appropriate. The question is, would there be a practical difference in performance between NECC DDR2 533MHz and 667MHz RAM for my trading software purposes on a Core 2 Duo platform, such that the Dell purchase should be ruled out? I'd appreciate any input from ET hardware enthusiasts.