@K1ash3r Yes that mobo is an AM3 mobo so it will support only AM3 CPUs and DDR3 RAM...But no crossfire as it has only 1 PCIe slot...
@ciberfog that mobo wont support AM2+ CPUs(X4 940) It supports the following CPUs...
X3 7x0, X4 945, x4 955, X4 810, X2 550...And would obviously support the newer CPUs that AMD might release...
And generally you wont notice much performance increase by increasing the RAM(Above 4GB)
And that X4 955 + Video combo surely would give you better performance than better RAM...
I wouldn't say DDR3 is the best but it is the way to go as newer CPUs will take advantage of the DDR3 speeds and DDR3 would slowly out-phase the DDR2 RAMs...
So if you don't plan crossfire, then that mobo is a very good option to consider as the money saved there can get you a better CPU...