The Guru of 3D posted a review on the Inno3D GeForce GTX 660 Ti iChill 3GB

Being based on the GK104 Kepler GPU obviously NVIDIA had to put some breaks on it in order for the 660 series of product not to compete too much with their bigger brothers. As such they trimmed down the number of shader processors a little towards 1344 of them. Now keep in mind that the mighty GeForce GTX 680 has 1536 of them so that's what, 15% less shader processors. More interesting is the fact that it's precisely the same amount of shader processors as the GeForce GTX 670 has, so you can already 'feel' where the performance levels are heading. There are two distinct difference though, the GeForce GTX 670 and 680 uses a 256-bit memory bus, and the GTX 660 Ti series will get a 192-bit memory bus tied towards 2 or 3 GB of memory. But with the memory running at 6008 MHz in combo with the memory bandwidth gDDR5 memory these days offers, really the difference will be noticeable but not that big. The second one is the ROP engine, now cut down to 24 units opposed to 32 on it's bigger brothers.

Not one AIC partner from NVIDIA will follow up with this at launch, but the reference product will be clocked at 915 MHz, it's allowed to boost towards 980 MHz (again similar to the GTX 670) and the TDP of the GeForce GTX 660 Ti is going to be set at 150 Watt, while in your average gaming experience the card really uses like 135 Watt.

So it isn't hard to understand that the factory overclocked GeForce 660 Ti SKUs will run as fast as and maybe even faster then a GeForce GTX 670 (reference clocked) and maybe .. just maybe even close in on a reference clocked GTX 680. The GeForce GTX 660 Ti series will be launched in the 300 USD range, 259 EUR ex VAT in Europe. And for that money it's going to shock and awe alright. Before we startup the review let me blast a quick myth our of the virtual skies, the rumor of a 256-bit version of this card has been denied by NVIDIA. And truthfully, if such a card existed .. it would be 1:1 a GeForce GTX 670.

  Inno3D GeForce GTX 660 Ti iChill 3GB Review