how much shared memory per SM in GTX 1080?

Nvidia’s white papaer https://international.download.nvidia.com/geforce-com/international/pdfs/GeForce_GTX_1080_Whitepaper_FINAL.pdf says 96KB of shared memory per SM, but Nvidia’s CUDA occupancy calculator (released as an excel file ) https://developer.download.nvidia.com/compute/cuda/CUDA_Occupancy_calculator.xls says 65536 bytes if you put in sm_61 for the compute capability. So which is it?

Is it because devices with compute capability of sm_61 have varying shared memory sizes, and the occupancy calculator is giving me a conservative number? Or is it because, even if 96KB of hardware shared memory is available, about 30KB of it is unavailable for some overhead stuff?

Looking at the .xls file you linked, it shows 98304 bytes of shared memory for CC 6.1. That is 96KB, and matches what is stated in the CUDA Programming Guide.

hmmm okay. I must not know how to use excel, or there was a problem while opening an older version of excel file with the newest one ( I bet its the former )…

Thanks!