Not to sound stupid but what is the clock speed I am supposed to buy for a Gigabyte motherboard that has DDR3 2100+/1333 listed as the "memory standard" I m looking at some DDr3 1600 Mhz Corsair but I want to make sure it will work
as long as its ddr3, it shouldn't matter. If you find its not running at full speed, you can always configure it manualy in the bios. I have to do that for my ddr2 1066. My board only wants to run it at 800Mhz. The main thing is u get the right ram for the slots you have on the board. In this case, ddr3.
it will definitely work, but it'll only run at the maximum speed supported by the board, in this case 1333Mhz. but if you're running a core i7 system, just make sure the ram is i7 ready, meaing that it doesn't run at a super high voltage that would fry the cpu.
My Gigabyte EX58 UD5 also supports DDR3 2100+/1333 as does their Extreme EX58 board.
All it means is you can use any DDR3 core i7 memory in duel or triple channel in 2,3,4,6,12gig-24gig capacities and you can use rated speeds from 1333mhz right up to and over 2100mhz DDR3 ram.
For example I have Corsair Dominator 1600mhz memory in mine. All I did was going in and tell the BIOS to load the memory XMP profile 1. The BIOS then upped my ram from the 1333mhz it first booted at to 1600mhz which is what mine is rated for. The process would be the same if you bought 1800mhz or 2000mhz RAM.