I have a pentium i5 quad core 3.4ghz. 8gb ram. and an nVidia gtx 560ti. I play in 720p on high and my FPS stays above 30 at "all times" usually ranging from 60-100, as low as I've "seen it go" is around 50. Every few minutes or so, and it gets worse the longer I have the game running, the framerate completely locks up. When it clears back up it shows a framerate of 1-5fps for 1 tick then returns to the usual 60-100fps. It doesn't seem to happen in menus, but it also doesn't seem to matter how much is being rendered on screen. Tons of mobs. No mobs. Tons of props. Few props. Tons of players. Few players. It still locks up on the regular regardless of what's going on in game every few minutes or so. It gets almost impossible to play after 30min - an hour. Any help or suggestions would be greatly appreciated.