Out of Memory

[Ulpix]

I've been having an obnoxious problem. After about 30 minutes of playing FTB, it lags out to the point I cant even open my inventory. Is there any way I could allocate more memory to FTB, or am I screwed?
PS - My laptop is the ASUS G55VW, so it's not like my computer cant handle minecraft. I normally play at 90-120 fps. Any suggestions would be greatly appreciated.
-Ulpix

 

[Meldiron]

What's your FPS when you've just started minecraft trough the FTB launcher?
And yes, the launcher have an option for giving minecraft more memory.

 

[Ashzification]

Need some more info

 

[Ulpix]

It's now fixed. I initially downloaded the .jar not .exe file, which apparently didn't want to cooperate.