Orin is based on the Ampere architecture, and has compute capability 8.7. The CUDA Toolkit tunig guide for ampere only mentions 8.0 and 8.6, specifically for the shared memory size here. The same is also true for the per-compute-capability feature list here. Table 15 on the same page mentions CC 8.7, with 163KB max Shared Memory per block, similar to CC8.0
However DeviceQuery reports a smaller number (~48KB, see below for reference).
I am wondering what is true.
/usr/local/cuda-11.4/samples/1_Utilities/deviceQuery/deviceQuery Starting... CUDA Device Query (Runtime API) version (CUDART static linking) Detected 1 CUDA Capable device(s) Device 0: "Orin" CUDA Driver Version / Runtime Version 11.4 / 11.4 CUDA Capability Major/Minor version number: 8.7 Total amount of global memory: 30623 MBytes (32110198784 bytes) (016) Multiprocessors, (128) CUDA Cores/MP: 2048 CUDA Cores GPU Max Clock rate: 1300 MHz (1.30 GHz) Memory Clock rate: 1300 Mhz Memory Bus Width: 128-bit L2 Cache Size: 4194304 bytes Maximum Texture Dimension Size (x,y,z) 1D=(131072), 2D=(131072, 65536), 3D=(16384, 16384, 16384) Maximum Layered 1D Texture Size, (num) layers 1D=(32768), 2048 layers Maximum Layered 2D Texture Size, (num) layers 2D=(32768, 32768), 2048 layers Total amount of constant memory: 65536 bytes Total amount of shared memory per block: 49152 bytes Total shared memory per multiprocessor: 167936 bytes Total number of registers available per block: 65536 Warp size: 32 Maximum number of threads per multiprocessor: 1536 Maximum number of threads per block: 1024 Max dimension size of a thread block (x,y,z): (1024, 1024, 64) Max dimension size of a grid size (x,y,z): (2147483647, 65535, 65535) Maximum memory pitch: 2147483647 bytes Texture alignment: 512 bytes Concurrent copy and kernel execution: Yes with 2 copy engine(s) Run time limit on kernels: No Integrated GPU sharing Host Memory: Yes Support host page-locked memory mapping: Yes Alignment requirement for Surfaces: Yes Device has ECC support: Disabled Device supports Unified Addressing (UVA): Yes Device supports Managed Memory: Yes Device supports Compute Preemption: Yes Supports Cooperative Kernel Launch: Yes Supports MultiDevice Co-op Kernel Launch: Yes Device PCI Domain ID / Bus ID / location ID: 0 / 0 / 0 Compute Mode: < Default (multiple host threads can use ::cudaSetDevice() with device simultaneously) > deviceQuery, CUDA Driver = CUDART, CUDA Driver Version = 11.4, CUDA Runtime Version = 11.4, NumDevs = 1 Result = PASS
Running device quer