$400 to upgrade, MB & CPU or GPU

[adminwizard]

SO here are the core basics of my system
AMD1090T processor with a 990fx chipset motherboard.
2 6870 graphics cards in crossfire config.
8 GIG of RAM and a 180GB SSD

The rig is great, I love it, but you just get that itch to change something.
My computer is mostly used for Gaming BF3 MWOnline Diablo III and WOW
I do some video editing, not enough to call it a hobby, I find it boring, but I am my friends and family computer guy so I do favors from time to time.
The wife has allowed me, for Valentines, to spend $400 on an upgrade to the rig.
I have two choices

New MB and i5-3570K
or
GTX 670 graphics card

both choices come to about 400 so I can do one or the other, but not both.

I think I would get more performance out of a new MB and CPU.
What does the community think? Thanks in advance for your response.

 

[djangoringo]

A 7950 or the 670 gtx will be the best option, you still have a good cpu, also the crossfire setup of 6870 is good for gaming, but if you want a single card...
The 7950/7970 offers two games like crysis 3 and bioshock infinite so it almost pays off.

 

[jay2tall]

I'd second a GTX670. Many of the models are based off the GTX680 board and are overclocked to that speed already plus has headroom for higher OCs. They also are being bundled with free stuff. The below looks like a good deal.

http://www.newegg.com/Product/Product.aspx?Item=N82E16814130787

 

[camohanna]

http://www.newegg.com/Product/Product.aspx?Item=N82E16814202008

or

http://www.newegg.com/Product/Product.aspx?Item=N82E16814202001

 

[jay2tall]

^MORE FREE STUFF! I Love free stuff.

 

[camohanna]

^MORE FREE STUFF! I Love free stuff.

Whos doesnt?

 

[adminwizard]

Thanks guys. I got the XFX 7970 Black Edition. So far, awesome card,
Bonus: a week later I won a Intel 520 SSD 180GB at a tech conference. Speedy Speedy Zip Zip!!