CUDA sample about bandwithTest

I have a question regarding to memory throughput of the Xavier AGX.
Xavier is in the highest performance mode (nvpmodel –m 0 jetson_clocks)
CUDA sample
/usr/local/cuda-10.2/samples/1_Utilities/bandwithTest/

In the specs it is written that the Xavier peek memory throughput is 137 GB/s and device memory, host memory, and unified memory are allocated on the same physical SoC DRAM.

Why is the bandwidth from device to host(host to device)only 30% of the standard value?

Device 0: Xavier
Quick Mode

Host to Device Bandwidth, 1 Device(s)
PINNED Memory Transfers
Transfer Size (Bytes) Bandwidth(GB/s)
32000000 37.5

Device to Host Bandwidth, 1 Device(s)
PINNED Memory Transfers
Transfer Size (Bytes) Bandwidth(GB/s)
32000000 37.3

Device to Device Bandwidth, 1 Device(s)
PINNED Memory Transfers
Transfer Size (Bytes) Bandwidth(GB/s)
32000000 108.1

Result = PASS

Dear @zzy3797777861,
Please post Jetson platform related queries at https://forums.developer.nvidia.com/c/agx-autonomous-machines/jetson-embedded-systems/jetson-agx-xavier/75.

1 Like

ok,thanks.