[vlovich123]

The API part isn't thaaat hard. Indeed HIP already works pretty well at getting existing CUDA code to work unmodified on AMD HW. The bigger challenge is that the AMD and Nvidia architectures are so different that the optimization choices for what the kernels would look like are more different between Nvidia and AMD than they would be between Intel and AMD in CPU land even including SIMD.

[pjmlp]

Only if the only thing one cares about is CUDA C++, and not CUDA C, CUDA C++, CUDA Fortran, CUDA Anything PTX, plus libraries, IDE integration, GPU graphical debugging.

[vlovich123]

CUDA C works fine with HIP not sure what you're referring to. As for the other pieces, GPU graphical debugging isn't relevant for CUDA and I don't know what IDE integration is special / relevant for CUDA but AMD does have a ROCm debugger which I would imagine would be sufficient for simultaneous debugging of CPU & GPU. You won't get developer tools like nsight systems but I'm pretty sure AMD has equivalent tooling.

As for Fortran, that doesn't come up much in modern AI stuff. I haven't observed PTX / GCN assembly within AI codebases but maybe you have extra insight there.