XFX HD 7870 and 7850 Double Dissipation Review @ OCC
 

In the end I have to say that I was very impressed with both XFX cards. However, I was more impressed with how close the XFX Double Dissipation HD 7850 was able to perform to the HD 7870. Considering the XFX Double Dissipation HD 7850 comes in at almost $100 cheaper than the HD 7870, it makes it almost a no brainer. Not only that, but we were easily able to overclock it enough for it to perform faster than a stock HD 7870, which again makes it a no brainer.

http://www.overclockersclub.com/revi..._7870_7850_dd/