I'm looking for an upgrade of my cpu. My current cpu is AMD Athlon IIx4 620(didn't overclock as I don't have much cooling)
I was going to buy the bulldozer but then I realized it needs socket AM3+ which I only got AM3 so it seems I have to go with phenom. I noticed that I need a cpu upgrade because last week I upgraded my graphic card and still metro last light and some other games was very unplayable with constant very low fps. I think atm my cpu is bottlenecking my gpu. I was thinking about getting either the phenom IIx4 965 BE or phenom IIx6. Thanks
Since your board only support am3 cpus, a phenom ii x4 955/965 BE would be your best choice ( but don't OC since you board isn't capable of doing that ). x6 ones offer lower core clock, thou. Not so useful for your games.
The highest performing chip listed by MSI for that board is the Phenom II x6 1100T, however for better single threaded performance, simply pick the Phenom II x4 or higher chip with the highest clock frequency that you can find available.