Of course it makes a difference... the peak transfer rate for DDR3 800 is 6400mb/s... the peak transfer rate for DDR3 1600 is 12800mb/s. If the ram you're running in a system that is of a comparable standard to your memory then upgrading that won't really make a difference, however if you put your memory in a higher power rig (not than you can because they're all DDR3) then it would all be bottlenecked by the memory. And the reason most people go for higher speed memory than is really needed is for more overclocking headroom, I think my 2133 rated sticks are only currently running at 1600. And of course tightening to speed up the clock cycles between RAM and CPU will make a difference. And I'm not 100% on this but isn't most haswell memory 1.5v so it doesn't really make a difference to the power consumption?! As to why the recommended system settings was saying you need a AMD 6 core cpu... probably because AMD don't make any good CPU's Back on topic, yes it should playable. Would you be getting anywhere near the potential of the game? No.