1333 vs 1600

Yeah, you won't probably notice if you are just internet browsing or text editing. On the other hand, if you are playing some heavy games as BF3 or Crysis 3 you will notice. Also, if you do image or video rendering, you will notice. I think that if you can get 1600 RAM, you should get it.
However, speed is not the most important thing. When you are choosing RAM, you should always pay attention to CAS Latency. A good RAM that has all of the things above is Corsair Vengeance 8GB 1600MHz C9.

http://www.newegg.com/Product/Product.aspx?Item=N82E16820233144

Hope I helped,

34xdxd
 


I thought 1600 was best for an intel cpu and amd utilized higher speeds better. Correct me if I'm wrong though. Regardless, with a cpu as old as his I wouldnt bother upgrading the ram till everything else was rebuilt.