12m ram overkill?

[JeffnWV]

picked up a workstation pc with 12m dominator 1600 ram (6 dimms)
has an i7 940 on an Asus P6T6 and putting in a gtx 295 (sli eventually)
System is running XP pro 64

From my research, the system wouldn't come close to using that much. is it overkill? (not using it as a workstation, was just a good price... <2/3 of component value based on Newegg)

Would Vista 64 be better?

[PrometheusCon]

In my opinion, as long as the ram is running together friendly and you are happy with the OC (or whatever speeds you have on it), you are okay. Overkill? maybe, but hey this is XS. I would go Vista 64 over XP 64 because you'll eventually need it for Quad SLI support and it'll be a having to redo the OS once you've already had it up and running. Might as well switch over now, ya know?

[lowfat]

I use 12GB of ram, however I don't run a page file since supposedly it is hard on my SSD's. And Crysis would always run out of ram when using 6GB.