With the 6300, I'd look to 1600/9 in a 2x8GB set, so the RJ X set I linked to before, (and while your mobo may be 'rated' to 2133, there's very few 8350's that can even run 8GB of 2133 at 2133 let alone trying to go 16GB...you could look for 1866, but no guarantee that your CPU could carry 1866....as far as CAS want the lowest you can realistically run with your CPU at the highest freq...for your CPU I'd say 1866/10 or 1600/9