RAM and CPU ratio?

Here is my system

-P4N Diamond MB
-650W powersupply
-1gb DDR2 Corsair XMS2 6400 (800mhz)
-WD Raptor 74gig SATA 10000rpm
-EVGA 7800 GTX
-Pentium D 830

I haven't gotten this comp up and running yet, becuase MSI is sending me a new BIOS chip with lastest version on it so it can run my Pentium D.

I just wanted to ask about the RAM. The mobo says that it takes up to 667 mhz ram and i read on the overclock part that you can overclock ram up to like 933mhz. So the questions are ....when i start up my comp what should the BIOS put the mhz of my RAM? Also if i overclock the RAM to 800mhz in the bios should it cuase any stability problems since the ram is supposed to run at 800mhz anyways?

Also since i have a Pentium D 830 at 3ghz fsb of 800mhz .....What will the ratio be for my comp and ram if the ram is at 800mhz?.. will that make it a 1:1 ratio and if not ..what will it make it?

Does the cpu/ram ratio have to be 1:1? Does it make your comp run faster if it is 1:1?

Anways any help/suggestions/advice would be much appreciated.