Well just that really... I am looking into buying a new rig and i have the choice, both are Dual DDR3, samsung 1333 or corsair 1600. Firstly is the 1600 even going to run at 1600 on my board or will it default at 1333 and will i even notice a difference? Will be used for gaming mainly online but might expand into single player/online fps
No you will not notice a difference. you may see 1-2 FPS in some games. But none in even more. If you want most bang for buck get the memory with the best timings (IE: 7-7-7-15 is bettter the 9-9-9-18).