So i just built my computer probably around three months ago. I had asked a friend who claims to know so much about computer. So i followed everything he had said in order to build a computer for games. At first it was fine. ALl the games i played ran just fine. However, some games now i have fps issue's, Such as GTA IV or Diablo 3. ANd many games that SHOULD run easily. I was told it was my processor and ram. Now im not very computer hardware smart. So im looking into getting a CPU at the moment. But i do now know which one to get. Im confused by everything. I don't wanna spend more then 200 dollars on a new cpu.
My specs are
SAPPHIRE Radeon HD 6870 1GB 256-bit GDDR5 PCI Express 2.1 x16 HDCP Ready CrossFireX Support Video Card
GIGABYTE GA-970A-UD3 AM3+ AMD 970 SATA 6Gb/s USB 3.0 ATX AMD Motherboard
if u want to stick with ur Motherboard, i would upgrade to the FX-4170 Quad Core chip which is somewhere at $125 i believe. For gaming, it does very well. You'll be able to Overclock that to 4.6 GHz which is no worries on the stock cooler for a 24/7 rig, but i would strongly recommend spending $50 or so on an aftermarket cooler. 4.6 GHz is the "sweet spot" for the Bulldozer chips.
I use the FX-8170 and for gaming and production. Only reason i went 8 core is because i make video games and A LOT of the times 8 cores helps a lot when switching from program to program and constantly running renders. Don't listen to all the fanboys on both AMD and Intel. An AMD chip will perform just fine on any game. There really isn't many games that REALLY pushes CPU performance. A great majority of video games don't really focus on CPU performance but more on GPU performance. Most games will use the CPU just for running state machines for loading and unloading. So it only calculates the numbers while the GPU will render those numbers. In your case, Diablo 3 and GTA IV are games that are very vast when it comes to the environment, so it's always in constant load and unload of the next area. Games like SC2 or LoL won't suffer so much because everything is loaded before the game starts. Hopefully that helps you to understand why certain games hog up CPU usage.
You might want to upgrade your ram as well. I say 8gb+ is safe. 4gb is bare minimum in my opinion and when it comes to games, sometimes RAM can interfere because it may not be sufficient enough space. Don't worry about the clock speeds of RAM. 1333, 1600, 1866, 2100... That hardly makes any noticeable difference. just stick with low latency ram, something like Kingston Hyper X or Corsair Vengeance. I haven't tried any G.Skill RAM but from what I've read, they do just as good.
In a few months the Piledriver chips are coming out so if you can bare the wait, it should be about a 10% improvement on the current Bulldozer chips as well as their going to be better optimized for Windows 8 if you choose to switch. I would say buy one of those when they arrive.