Answer by Cameron · Sep 15, 2012 at 04:26 PM
Minecraft is horrid with the way it was coded and lags all the time, even on great computers.
Here's a screenshot of my settings (I get about 60 FPS)
You can also download a mod called "Optifine" which auto-tweaks the Minecraft java file and makes it more optimized for play on slow/old computers.
Answer by Combatman12 · Oct 07, 2012 at 03:50 PM
You can find a texture pack that is simple and that could increase fps by 10-30. You can also download something called gamebooster which temporarily closes unwanted processes and boots them back up after you finish gaming.