Just bought minecraft alpha, and there's SO MUCH LAG! I've tried everything, from heightening the priority to using Gamebooster, turning the settings down to a lower quality, and adding fog. My specs aren't that bad:

AMD Athlon 64 X2 5200+ @ 2.700 GHz

2 GB of ram

NVIDIA GeForce 6150SE nForce 430 (integrated)

I know it's not the best, but it should be good enough not to lag on Minecraft, right? The only thing I can try is putting in a different graphics card (older, but dedicated, so it should free up some ram).