Help with choosing RAM DDR3

[Goldsun1715]

Hello, I need help with picking my RAM, this computer was pre-built with Corsair RAM, but I'm having trouble with choosing the exact one.

My CPU-Z (I really don't know if this will help): http://valid.canardpc.com/show_oc.php?id=494339

Does my RAM speed look correct? I'm a noob to this and I just want to upgrade to 6 gigs of ram, what should I get?

I have overclocked my System to 3.8GHz.

PC:

Corsair TX750W PSU
Intel Core i7 920 OC'd 3.8GHz
3GB of Corsair RAM
2x 500 GB HDD
4870x2 Sapphire

 

[J Coffey]

You have a P6T DELUXE, which I am pretty sure has 6 ram slots.
So just get another 3, 1 gig, 800 mhz sticks or ram like you do now and stick them in your computer.

And what does you mean buy your ram speed looking correct? 800mhz is pretty common.