Dont!
4 GB Ram = Overkill
6000 = Overpriced, get an E6600, it's faster, cooler, cheaper etc.
Get a nice Asus P5K to go with and a new fan and for the same price you've got a lovely overclocking PC if you need it
...?
What do you mean "if your processor isn't fast enough" - the amount of RAM is limited by the mobo (although i'm sure theres some silly limit like 1 TB on the CPU). Heck, on an Intel system the CPU doesn't even have anything to do with the memory because the memory controller is on the mobo!