I just built my moms new PC (vista 64) and love it so much that I wish to upgrade to vista from XP. I have a core i7 920, 3GB(3x1) of DDR3-1333, and an ASUS P6T. I use my computer primarily for gaming and don't want any major slow downs in framerate and overall "snappiness" compared to XP. (a minor reduction in FPS is fine though).Would it be worth it to run vista on only 3GB of ram or would I want more?
You'd want another GB if only so that you can run that RAM in dual-channel mode (or is it quad now?). Besides, if you're upgrading to 64-bit, you might as well take advantage of the fact you can make use of 4GB+ of RAM.
Well, with the core i7 it's either get 3 or get 6, right? And DDR 3 is still rather pricey, last I checked anyway.
The short answer is that three will be plenty but I would sure get 6 if I could possibly afford it - it's a bit of a luxury but over time you will be glad you have it. Having said that I don't think you would find a three gig system will be sluggish in any way - Vista is not that much of a memory hog really. That's a myth.
Frame rates with XP are essentially equal now. More RAM might help some with frames, according to Corsair.