What RAM should i buy?

What is your budget? A good place to start is just looking on Newegg, with the spec's you want, and reading some of the reviews. When talking about overclocking, are you talking about OC the RAM or the CPU?

What are you doing with the computer? (This may affect how much RAM you want to get).

What OS will you be using? Will it be 32-bit or 64-bit?

this... http://www.newegg.com/Product/Product.aspx?Item=N82E168...

1600 ram? I think I would get a set of cheaper 1333 ram. Its going to be mated to a slow FSB, so the faster stuff isn't needed. I'd only get the 1600 if you plan on reusing it in a newer rig. Seeing as you just bought the 790 board, I doubt thats the case.

This memory has great reviews and according to corsairs memory finder it is compatible with your mobo and it is 1.5v so there is plenty of overclocking capability. 4 gigs will run xp, vista, and 7 while playing any game, so dont worry about that unless you are running several memory intense apps at one time. I also agree with 4745454b but if you do want 1600 for a future rig I also added a link for that to.


CORSAIR XMS3 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1333 (PC3 10666)
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

CORSAIR DOMINATOR 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800)
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

With the MIRs those look good imo

i brought http://www.newegg.com/Product/Product.aspx?Item=N82E168...

Try to ensure whichever RAM you choose from the recommendations here will run in dual channel mode on your mobo. I think then it will double your data throughput.