Okay, I want to make sure that I understand things correctly. Let's say I get a mobo that has a 800/533 MHz FSB. Let's say it supports a Pentium 4 CPU 533 MHz FSB and dual channel DDR2 667 MHz RAM. So I put the 533 MHz FSB CPU in the mobo and I put a dual channel memory kit (DDR2 667 MHz 2x512) into the memory slots. For optimal performance do I need to have the memory clock back to 533 MHz? Also, does the mobo FSB usually clock back to what the processor will support, or might I need to force it to run at 533 MHz as well? Is having all of the FSB options and memory speed running at the same speeds (in this case 533 MHz) the optimal solution?