how much shared memory per SM in GTX 1080?

Accelerated Computing CUDA CUDA Programming and Performance
#1

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?

#2

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.

#3

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!