So I just got my new computer. I originally ordered it with 512mb of ram so I could take that out and put in my 4 gigs that I bought. The ram is pc2-6400 800mhz ram, but its only running at 333mhz, what the heck?

I have this motherboard: http://www.hothardware.com/Articles/MSI_K9A2_Platinum_AMD_790FX_Motherboard/

And this ram: http://www.newegg.com/Product/Product.aspx?Item=N82E16820227195

I've never had to do this personally, but it looks like you'll need to go into the BIOS and set up the RAM yourself.

Set the voltage to 1.8V and then you can set your RAM to the correct speed.

This page here is your ram, and they say that

n order to boot on some motherboards this product is programmed to 667MHz; to run at 800MHz you will need to manually set the speed to 800MHz and voltage to 1.8V in your BIOS

The 667 they talk about is your 333 double pumped. Breath a sigh of relief, it appears your RAM is working fine :)