Ok so... I have a GTX 660 and an i5 2500k, yet i still have lag in minecraft. No lag in other games though. Vanilla MC runs at over 500 fps on super flats and like 200+ regularly. Feed the beast runs at 50 fps with messed up laggy spikey things.
I really want this fixed, i tried adding javaw.exe to the nvidia control panel but it didnt help, new worlds don't help, optifine also doesn't help. You can see the lagometer in the video. It's playable, except not very smooth like vanilla.