Which AMD Cpu to get?

[Desttt]

I'm needing a new CPU/Motherboard for gaming, amongst other tasks. I'm mostly looking for something that will be able to run any game fine and for years to come (and not too pricey). I used this site, http://www.build-gaming-computers.com/gaming-desktop-computer.html, for help on a budget gaming build.

My price range is $150 - $200 for both.
From that site, I think I am going to get the GIGABYTE GA-970A-DS3 AMD 970/SB950 AM3+ for my Motherboard, but not 100% sure yet. Since I might need a better Motherboard to be as decent as the CPU.

As for CPU, I'm thinking either Quad or Six Core:
AMD FX-6100 3.30 GHz Six Core AM3+ (from the site I mentioned), AMD FX-4170 4.20 GHz Quad Core AM3+, AMD Phenom II X4 945 Quad Core Processor, and Athlon II X4 640 Quad Core.

Now out of those 4, which would be the best for gaming, while having loads of other programs running in the background, etc.?
Also, my Power Supply is a OCZ ModXStream Pro 600W so hopefully the 95w and 125w difference from these CPU's and Motherboard won't make it so I need to get a new PSU as well.
Thank you for taking the time to read this post and any help/advice is much appreciated!

 

[DJDeCiBeL]

Out of those 4, the 4170 because of brute force speed.

The Phenom II X4 945 and Athlon II X4 640 are a bit slower than the 4170 (the older architecture of the Phenom II and Athlon II is much faster, but those two in particular would be slightly slower) and the 6100 is a lot slower.

I would say get either the 4170 or a 965BE. At stock speeds, they're basically equal.

Also, why not wait a few days to see how Piledriver performs? This is really a very bad time to be buying a Bulldozer CPU. Piledriver should actually come close to the Phenom II's, performance wise.

 

[Emerald]

if I would get a 900 series CPU it would be a 965, 970, or 980.

the Athlon II X4 640 does not have a L3 Cache

most games don't use more then 4 cores; therefore, the FX-4170 might be your best pick.

as long you only use one video card the PSU should be fine

 

[BuddiLuva]

I was going to go with the FX series but heard it was horrible
Ended up going with the Phenom 965 oc'd it to 3.6-3.8
Works nicely

I have a CX600 600w CPU and it works fine even with the HD6870 that draws about 150w just for itself