Son_Of_Diablo

Hello So I have set up a server running Attack of the B-Team mod pack, and it's all working just fine, except that when I play on my laptop it for some reason get these extreme lag spikes after 10 minutes or so my game basically freezes and get some small spikes where it runs fine. When my brother plays on his pc there is no problems at all and in normal minecraft my laptop gets up to 120 FPS. I have been searching on google but can't find anything that can help me out (This lag problem also happens when I play singleplayer) I have a Lenovo Y500 running Windows 8.1 if that can help? Please if anybody can tell me how to fix this it would really be nice! Many thanks for reading