Thinking about adding more memory...should I buy exactly the same?

[iolas]

I have a gaming PC with currently 2 sticks of 2gb of this memory on this board with an AMD BE 955.
Should I just buy two more sticks of that memory or should I buy some 1600?
Could I grab 2 4gb sticks and have those running with the 2 2gb sticks?
What would run the best? Thanks.

 

[geofelt]

With different ram specs, you will run at the lowest common denominator of specs, if at all.

Two more sticks of the same part number should work, but manufacturers have been known to change parts, even of the same part numbers, resulting in incompatibilities.

Ram is cheap, I think I would get a 8gb kit of 2 x 4gb that is supported on your motherboard.
With the old ram sticks , you could try it, but I would sell them. 8gb should be plenty.