So, IK you need two identical chips for dual channel, my only question is that should all 4 of your chips be similar? Atm I have x2 2GB ram chips DDR3 1333 PC 10666, and I want to get x2 4GB ram chips with higher speeds and what not. Is this recommended? The two 4GB chips will be a dual channel kit.
Your best bet is to get a single set of the full amount of DRAM you want, mixing DRAM from different packages, even the same exact model can and often is problematic. You can often get mixed sticks to play with timing/voltage adjustments, but not always
Well originally I was looking for a little more than 8 GB, because some games require that and I don't want to be on that border. 16 GB is out of the question because of the budget. My mobo is compatible with DDR3 2000(O.C) (Not sure what the O.C means), 1866, 1600, 1333. Generally the higher the number the better it is? Also the only thing for RAM about compatibility you need to worry about is with the motherboard right? Or does the CPU need to be to? And if so what do you need to look at to tell it's compatible?
What CPU? That's generally the determining factor more so than the mobo (which does play in), the mobo has to be able to run the DRAM freq (generally based on the chipset), but the CPU's MC (memory controller) is more the determining factor, i.e. a mobo may run 2000 sticks but if you have say a AMD 955 you'll generally be lucjky to run 1600 sticks