Over at Asian website Coolaler initial numbers of the GeForce GTX 750 Ti, that is rumored to be on Nvidia's new Maxwell architecture (still on 28nm btw) have appeared. You'd expect the card to sit inbetween GTX 660 and say 760 performance, but according to the early numbers, the card is 10% slower than a GeForce GTX 660.
Do keep in mind these are unreleased, unofficial, with non-final drivers results based on a card that officially has not been released.
GeForce GTX 750 Ti "Maxwell" Performance Numbers Leak
