Quote from Blackice504
lol most Minecraft servers not even use 12GB and other games like say Crysis 2 just only uses 4GB so using all that ram will not make a difference as minecraft ( Client ) would peak at 1.5GB running for 2 days, 30FPS is fine as most LCD's only do about that a dvd movie ( non bluray is 25FPS for an example. so if your getting 30FPS that should be fine i am getting 60FPS with same gpu, so i would look at what drivers you have and make sure you got ver 0.8 and the shader files for 8.
other settings you might want to look at is mip maping level / what mip maping type you have ( linear or nearest ) and your Anti-Alisasing level i surgest turning AA off as it makes some blocks look like they have a line around them as most texture packs or the way minecraft it self works does not use or do a good job with AA.
I turned off NVidia CP AA and Anisoptric filtering, but it only boosted it by ~10 fps. I'm using only v08 files, and my NVidia driver is 301.42