If you have the Money, a 7950 is alot better than GTX 660.
Its on the par with GTX 660Ti
And I must warn you about Gigabyte they have Voltage Lock, So you'll not be able to Overclock.
Thank you for your reply!
I know my post is just created but i have decided to buy a HD 7870 its costs alot less and it perfecly fine for gaming for another 3 years maybe (first high-at the end medium settings) and then il buy a new mid/high card for 200 euros : )
So i have a little more to invest for a 3570k
And even safe a little
Now i look at your benchmark cart the hd7870 isnt bad at al !!
And it goes fro the same price as a gtx 660