Major difference in FPS with some games, FPS too low in others, why?

[PS3toPC]

I know Warface isn't hard to run but, in Warface on the highest settings with V sync on, i still get the FPS of 120 at all times, But in ArmA 2 OA (DayZ mod), i am mainly getting around 15 FPS, but here is whats weird about those crappy 15 Frames, It doesn't matter what settings i am on and what resolution, it's still stays the same (apart from when i set the 3D Resolution about 150% and above.)

Why am i getting these frames, Is this normal? Is there anything i can do to fix this? (I have already done these FPS improvements On YouTube and stuff..)

Specs:
CPU: Intel Xeon x5355
GPU: MSI R7 250 2GB OC Edition. (Overclocked)
RAM: DDR2 (I Know) 1x8GB
Motherboard: Dell dt029 (For The Dell Precision 690)

^Or are these the problem^

 

[bystander]

Every game is different. Every game has different demands. Arma has a reputation as having about the worst online multiplayer performance of any notable game.

If settings have little to no effect on performance, your GPU is being bottlenecked by something. Most likely the CPU, but it could be internet related.

Is that CPU at stock clocks? They have tons of room to OC, to allow you to see if that would help.

 

[PS3toPC]

Every game is different. Every game has different demands. Arma has a reputation as having about the online multiplayer performance of any notable game.

If settings have little to no effect on performance, your GPU is being bottlenecked by something. Most likely the CPU, but it could be internet related.

Is that CPU at stock clocks? They have tons of room to OC, to allow you to see if that would help.

Yes it is, I have no idea if my CPU is even overclock-able, never tried. how would i overclock it?

 

[bystander]

You'd have to search, and have a MB that can OC. Given that is a Dell mobo, there is a good chance it can't. Search on how to OC with that CPU and motherboard in the search parameters.

 

[PS3toPC]

You'd have to search, and have a MB that can OC. Given that is a Dell mobo, there is a good chance it can't. Search on how to OC with that CPU and motherboard in the search parameters.

Thanks for your support, i am gonna go ahead and see what i can do, thanks again!