The GTX 660 Ti is a good card for gaming up to 1920x1080. Suggested pricing is €259 + VAT, which pits it against the HD 7950 rather than versus HD 7870. HD 7870 cards currently start at €260, while the 7950 can be found at €290. As far as performance goes, the GTX 660 Ti is somewhere in between, largely depending on the game and resolution.
We’ve seen that the GTX 660 Ti is capable of beating the HD 7950, but the highest resolution and antialiasing take their toll on the GTX 660 Ti.
The card has a nice performance per Watt ration and quiet cooling. Perhaps 1344 CUDA cores and 2GB of memory on the GTX 660 Ti may harm GTX 670 sales, but the latter still has the upper hand. The GTX 660 Ti comes will less ROPs and 192-bit memory interface, which shows in the tests.
Overclocking the GTX 660 Ti matches the GTX 670's performance, not too shabby considering that the GTX 670 goes for €370. On the other hand, the GTX 670 is a fine overclocker itself, and it lets you match the GTX 680, so let's not go down (or up?) the rabbit hole.
If you're lookign for a new graphics card, the GTX 660 Ti will provide all the benefits of the Kepler architecture. We've seen in our tests that the GTX 660 Ti outran the last year's top card the GTX 580, which really says enough.