Some differences between the GF100 cards could thus be based on the integration of a lower number of SM for each GPU, leaving the CUDA core numbers untouched; disabling 2 SMs, the result is a GF100 GPU with 448 CUDA cores, a number that nVIDIA has also indicated in some internal documentation that was made public online, referring to the Tesla family Fermi solutions.

Let’s check in detail how a streaming multiprocessor is made. The central part has 32 CUDA cores: each group of 4 is associated to two load and store units (LD/ST), while 2 of these groups are associated with a Special Function Unit (SFU), for a total of 8 CUDA Cores. We can find also an instruction cache, followed by two Warp Schedulers and two Dispatch operation units, connected to the file register and capable of managing up to 32.768 32-bit entries.