Asus GTX 670 vs Asus r9 280x

I have a friend of mine who currently is running 2 Asus GTX 670 in sli, he is looking to sell them.  I however am at this time only interested in buying one of the two.  I have a friend who is currently looking for a new graphics card(currently using 7870).  The only deciding factor is if my friend buys one of the two, and right now he needs a bit more convincing.  He currently is looking at getting a Asus r9 280x.  Links down below are of the card my friend is selling first, then the second one is the r9 my friend is looking at, any help or ideas are appreciated.  I personally think the 670 beats a 280x but, i cant find much as far as facts on that.  

Asus GTX 670

http://www.newegg.com/Product/Product.aspx?Item=N82E16814121707

Asus R9 280X

 http://www.newegg.com/Product/Product.aspx?Item=N82E16814121803

The gtx 670 does edge it out but just barely. If they are even close in price i would just go with a new r9.

After OC the 280x wipes the floor with the 670. 280x is closer to 680 or 770, and frequently beats those.

This thread is a double post.

+1

well if its for 200$ it would be the better deal, but if its the same price then yes you are right.

Where did you find a $200 670?

The 670 is a good card. But at that same price, might be able to pick up a 7950.

It does come down to the games, but with the extra Vram, the AMD cards are a much more complete solution.

ebay. no box just the card seen many of them go for that.