Which are the motherboards that support AMD Phenom II x4?
As mentioned before every am3 socket motherboard will be fine.But I see a flaw in your plans,the 6gb of ram.If you are ploanning to get a phenom 2 x4,you will have to use dual channel memry or you will suffer from a reduction i performance if you go single channel.To explain it better,dual channel comes at these sizes 2x1gb=2gb,2x2gb=4gbs,2x4gb=8gb and so on.6gbs are only achievable by either single channel configurations which will be slower or triple channel ram the which if you get am3 or am2 you can’t have because they don’t support it.So you either go x58 aka i7 9xx series or you forget the 6gb and get 4 or 8.
