Very bad Stuttering in Ubuntu 12.04

The game seems playable for a minute or so then it just becomes very choppy, lots of stuttering and what not. I have set the details to lowest settings. If I minimize the screen with Ctral Alt Arrow It seems to restore the game for a few more minutes but this makes the game crash sometimes.
-Intel Quad core cpu
-Nvidia driver 319.32
-4 gigs ram
-intel SSD
-Ubuntu 12.04