Will this mobo support SLI or Crossfire

That board will run crossfire only.

What CPU do you have or will be using? I would advice not buying a P35 mobo new as it is pretty dated, unless you already have it.

I already have it in my current system along with a Core 2 Quad Q6600. I am currently running a 8800 GTS 512MB (G92) and I upgraded to a 28" monitor and the card has a hard time keeping up with WoW in certain areas and raids. And I want to hook up my other 20" widerscreen monitor along with it. I was hoping to not have to upgrade my whole PC right now

Also how can you tell it runs only Crossfire?

Because the only boards with Intel chipsets that I know which run SLI are specific ones for the newer i5 and i7 cpu's. They have an nvidia chip on the board for SLI. Here is the product page, it only lists Crossfire. http://www.gigabyte.com.tw/Products/Motherboard/Product...

Crossfire on that board is only x16 and x4 on the 2nd card. So realistically Crossfire isn't really worth it. Since you listed (2) gts 250's I assume your price range is about $300. I would buy a 5850.

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

I agree with jay2tall. You do NOT want to run Crossfire on a motherboard that runs its second slot at 4x. You're much better off just getting the best single card you can afford.

On the Product page you listed it says this "Ultimate graphics performance with dual PCI-E x16 interface" Wouldn't I use the 2 PCI-E x16 interfaces for Crossfire?

Marketing gimmick. It is two physical PCI-E 16x slots, but I can already see from the picture the second is 8x electrically at most.

Even though the second slot is of 16x physical length, only 4 lanes are wired to it while the first slot always has 16x lanes. Using crossfire in an uneven lane configuration, like 16x and 4x, causes unpredictably and often poor performance compared to a system that uses two 8x or two 16x lane slots. You may want to instead go with a single high performing single card like a Radeon 4870X2 or the 5850.

By the way, a single GTS 250 is pretty similar to your current 8800GTS 512MB. The former uses a G92b chip, which is just a die shrunk G92 chip, which is used in the latter, with slightly higher clocks.

Thanks for your help guys. Now I need to find out how long the 5850 or the 4870x2 is. Would you recommend a Geforce card over the 5850 in the same price range? Would the 5850 be able to handle the 28" monitor and the 20" also? I would be gaming on the 28" and have a browser or a streamed broadcast on the second screen