Why does the magma_dgemm function not use tensor cores on the V100 GPU?

Question

I run MAGMA testing_dgemm code both on V100 and H100 GPU. With Nsight Systems, I found that on the V100 the code doesn't use tensor cores, but code on the H100 it does.

V100 result:

H100 result:

The tensor core has been used in Volta GPU according to NVIDIA web.

The NVIDIA Inside Volta blog seems not to mention the FP64 TC performances.

Answer 1

The v100 GPU doesn't have a FP64 (double precision) path in its TensorCore unit.

That path/capability was introduced in Ampere A100 3rd gen TensorCore.

So when performing FP64 arithmetic, V100 generally will not use TensorCore.

From here:

NVIDIA A100 introduces double precision Tensor Cores ...

(emphasis added)