PC Perspective has published a performance review of the NVIDIA GeForce GT 640M, the first Kepler GPU to hit retail shelves. The chip is found in Acer's new Aspire Timeline Ultra M3, you can check out the benchmarks over here.
The reviewer concludes the performance gain between this generation and the last (GeForce GT 555M) is substantial, but noticed that the chip seems to be giving off quite a lot of heat, although this could be the result of the inadequate cooling provided by the ultrathin chassis of the Timeline Ultra M3 ultrabook.
The performance gain between this generation and the last is substantial. Overall, the GT 640 appears to offer performance on par with the old GT 555M. This should have the effect of lowering the money you have to spend to buy a laptop with acceptable 3D performance. Our Acer Aspire review unit has an MSRP of $799, which is quite a bit less than systems available with the GT 555M.
Intel HD 4000 graphics will, of course, change the balance of this equation somewhat. Thanks to the leaks from Anandtech we already have a decent idea of what that part will provide, and it’s not bad. But it seems Nvidia will be able to offer value beyond integrated graphics.