In terms of gaming performance, which card is better...

[Gary Lowe]

Running 1 monitor at full HD, I want a card around the £200-300 mark that will run games at decent frames (BF4 here we come!), last me a long time
Will be running it on i5 3570k, so no bottling to be worried about.

Cards im currently looking at:

SAPPHIRE AMD Radeon HD 7950 Vapor-X 3GB GDDR5

Club 3D Radeon HD 7870XTV JokerCard Never Settle Reload Graphic Card

And possible a 660/670, depending on their performance against the above cards...

 

[yasserBasha]

If you have the money then the gtx 670 wins hands down :

http://www.anandtech.com/bench/Product/548?vs=598

in every aspect it smokes the 7870

As for the 7950 it's push-and-pull :

http://www.anandtech.com/bench/Product/550?vs=598

this is the regular version

http://www.anandtech.com/bench/Product/645?vs=598

AND this is the boost version of 7950, you will see that they are almost head to head
But of course the radeon wins in power consumption plus the
VAPOR-X stands out with it's cooling solution

you look ... you decide

 

[huilun02]

If you are going to overclock, a 7950 can beat the 670.

Otherwise, 670 is better.

If you are willing to spend a bit more, this will smash the 670:
http://www.amazon.co.uk/Sapphire-Radeon-HD7970-Graphics-384bit/dp/B008V25EWI/ref=sr_1_4?s=computers&ie=UTF8&qid=1365428029&sr=1-4&keywords=hd+7970