VideoCardz have managed to get a hold of the new Nvidia GM107 GPU die layout. The GM107 is based on the next-generation Maxwell GPU architecture and according to rumours it contains a very different layout to its predecessor “Kepler”. In the GM107 die, which is expected to form the GTX 750 and GTX 750Ti, there are five SMM (streaming multiprocessors) blocks which each contain 128 CUDA cores. This makes it different to Kepler where one SMX unit contained 192 CUDA cores. If these rumours and the above image is true it means that the GM107 features 640 CUDA cores. Apparently all five SMM units are enabled on the GTX 750 Ti meaning it gets all 640 CUDA cores while the GTX 750 is rumoured to have one of these disabled meaning 512 CUDA cores in total.
Apparently the GM107 and another smaller (read: slower performing) chip, the GM108, are both to be built on the 28nm process with the Maxwell architecture. In terms of the higher end the GM206, GM204 and GM200 are the three GPU dies that will succeed the GK106, GK104 and GK110 respectively. These GPUs are expected to be built from Maxwell with a 20nm, not 28nm, process.
Image courtesy of VideoCardz.com, Via TechPowerUp