Adding RAM I need quick advice

Hello Tom's Forumers,

I have a Q6600/Asus P5B-Deluxe combo with of 2Gb OCZ DDR2 PC2-6400 Gold GX XTC Dual.

I recently bought G.SKILL F2-8000CL5D-4GBPQ PC2-8000 4GB 2X2GB DDR2-1000 CL5-5-5-15 240PIN Dual Channel Memory Kit.

I've been playing some FPS lately (FEAR,CrossFire) and i was wondering,

Can i add the new 4Gb to the 2Gb OCZ ram? I have enough slots but i remember from class your not suppose to mix?

I'm not sure. Should i just add the 4GB and sell the other 2GB?

Thanks everyone

I just realized because im running xp(32bit),
I need to upgrade to Xp(64). So i've done so,

Advice still needed though

As drippyfausett said, its not reccomended. If you mix it and lets say it works, the new ram will have to run with the speed of the old ram and you will also loose dual-channel mode, as that requires having matching modules in pairs. If youre using xp 4gb is more than enough plus you wouldnt see any improvement in performance between 4 and 6gb. Sell the old ram

Hehe thanks guys!

Okay just to clarify, i can run both sets in dual channel correct?
Beacuse i have 2x2gb and 2x1gb= 6gb

I think i will switch to either Vista or X-64 so i feel the RAM difference.

But looks like i should sell the 2x1gb sticks?

Thanks a lot

Basically both sets have to be able to run at the same settings: timings, voltage and speed. IF they work together at all, they will run with settings of the slower sticks. I would keep 4gb only,and maybe when you actually need more in future add another matching 4gb kit.