Help with GPU

[ThelMightylThor]

Hey so I am building a gaming computer and this is my basic setup so far...

Processor: AMD FX-8320 CPU (8x 3.50GHz/8MB L2 Cache)
RAM: 8 GB [4 GB X2] DDR3-1600 Memory
Motherboard: ASUS M5A97 R2.0

So the question is of the GPU, I am not all that knowledgeable about this subject and need some help deciding but can't break the bank so here are a few I have found.

1. AMD Radeon HD 7850 - 2GB
2. NVIDIA GeForce GTX 660 - 2GB - EVGA Superclocked - Core: 1046MHz
3. AMD Radeon HD 7770 - 1GB in Crossfire Mode

So which would run the best with my system? Does it actually help to have both an AMD processor and GPU or is it okay to mix and match?

Thanks in advance for all help.

[David (PassMark)]

Either the HD 7850 or the GTX 660, there isn't a dramatic difference between them.

Yes, you can use a nVidia card in a AMD machine.

[godfather]

The GTX 660 will give you the best performance. And I know this sounds counterintuitive, but many review sites have shown that the FX AMD CPUs work better with Nvidia GPUs because AMD GPUs are more platform dependent (rely more heavily on a powerful processor).

Read this for details if you're interested:
http://www.tomshardware.com/reviews/...neck,3471.html

[FastTurtle]

Change the system memory to the fastest the board supports. You'll get better overall performance with it across the entire system, not just the video performance. Does not apply to Intel as they don't support more then 1066/1333 and some 1600 speeds.

If this doesn't give enough performance, then you look at a dedicated video card but if you're going that route to begin with, why use anything with an integrated GPU? Think about it.