Would 4GB of 1866Mhz or 8GB of 1333Mhz RAM be better? The use is mainly gaming. I have an i7 860 and a Gigabyte GA-P55A-UD3 motherboard. I just bought an ATI 6970, so I won't be upgrading anytime soon. Will games need more than 4GB of RAM at any point in the next 2-3 years? How much does the RAM speed affect the system and gaming?
I would certainly pick the 8GB of 1.3GHz RAM, capacity of the RAM is more influential on gaming performance than the speed generally. I doubt any game is going to be using more than 4GB to run in the next couple of years though, having said that however. Technology is rapidly improving.
I currently have 4GB of 1866Mhz CL9. I have it clocked at 1450Mhz CL7. I was trying to decide whether upgrading to 8GB would make sense since it's getting so cheap. If I did upgrade, I would probably get 1333Mhz CL9. Would lowering my RAM speed really have no affect on my gaming? Would the additional 4GB actually help? Do you have benchmarks?
You are set up nicely with your current memory at 1450 CL7. I would not upgrade to anything CL9, rather match what you have and run 8GB @ 1450 CL7. For gaming you are fine with 4GB unless you are seeing your resource consumption going way up...
Faster ram is worth perhaps 1-3% in fps.
No game out now will take advantage of more than 4gb of ram.
If you will be exclusively playing the game, and no other multitasking, 4gb will be fine.
There is some argument for more than 4gb though, read this Corsair document: http://blog.corsair.com/?p=65