Hi, I have never ever seem to of had this problem before with IC2. I just recently put some mods together and realised that it kept freezing a stuttering and I finally narrowed it down to IC2. I ran IC2 on its own with just forge and my CPU was maxing out at about 97-100% usage which is crazy. I ran all the other mods (about 50) without ic2 and my CPU was running fine at about 70%.
I have an Intel Core i3-2100 3.10GHz in case you were wondering with 8GB of ram and I have never had this problem before.
Any help would be appreciated.