[Solved] System Bottleneck

Hello,

Long time reader, first time poster. I believe there is something bottle necking my system because I am noticing substantial lag when I play a few games and on top of that I struggle to run many games on medium let alone high settings. The games I've been playing are Arkham City, Assassin's Creed Brotherhood, and Battlefield 3. My sytem specs are as follows:
CPU-AMD Phenom II x4 965
GPU1-MSI GTX 460 cyclone
GPU2(Physx dedicated)-XFX gts 240
MOBO-ASUS M4A78T-E
PSU-Corsair HX850
Case- Cooler Master HAF 932 Advanced
Ram-4 2gb Ripjaws F3-12800CL7D-4GBRM

Anything advice you can offer to help me isolate this problem would be appreciated. Thanks!

Did you overclocked your cpu ? If not give him a little bump.

Thanks for the replies! I have not overclocked the CPU but that is something I've wanted to do for a while. I'm mainly hesitant because I don't want to damage anything. I've looked into it and there is soo much varied information out there about overclocking. Does anyone know a reliable how to guide, or tutorial that I could follow?

Best answer selected by bobsaget541.