Windows .exe Lag and then freeze.

[OERB57]

Hello everyone, i've been having problems with FTB. Whenever i go to play on a world after 3-10 minutes i get some lag spikes which grow longer and longer and longer, and then eventually the game freezes( It shows in the toolbar "(Not responding)"). If i try to exit during this period, it sometimes says "Shutting down internal server..." and then never moves.
I've tried adding this:

-XX:PermSize=128M

to advanced options and i've also tried upping my RAM allocation from 1.0 GB to as much as 2.0 GB. I also monitored my RAM in F3 but it never goes above 80% (This was before RAM allocation. Now it doesn't ever go above 50%).
It is really annoying please help .

 

[UniZero]

Backup your world first.

Then do the steps here first to make sure that the launcher is installed the correct way.

If you still have issues then go here for help with getting and posting logs.

Also check out this thread regarding JVM arguments.