What is OpenCL? AMD GPUs support CUDA. It's called HIP. You just need a bunch of #define statements like this:

    #ifndef __HIP__
    #include <cuda_fp16.h>
    #include <cuda_runtime.h>
    #else
    #include <hip/hip_fp16.h>
    #include <hip/hip_runtime.h>
    #define cudaSuccess hipSuccess
    #define cudaStream_t hipStream_t
    #define cudaGetLastError hipGetLastError
    #endif

Then your CUDA code works on AMD.

OpenCL is a Khronos open spec for GPU compute, and what you’d use on Apple platforms before Metal compute shaders and CoreML were released. If you wanted to run early ML models on Apple hardware, it was an option. There was an OpenCL backend for torch, for example.

Can you explain why nobody knows this trick, for some values of “nobody”?

No idea. My best guess is their background is in graphics and games rather than machine learning. When CUDA is all you've ever known, you try just a little harder to find a way to keep using it elsewhere.

People know; it just hasn't been reliable.

What's not reliable about it? On Linux hipcc is about as easy to use as gcc. On Windows it's a little janky because hipcc is a perl script and there's no perl interpreter I'll admit. I'm otherwise happy with it though. It'd be nice if they had a shell script installer like NVIDIA, so I could use an OS that isn't a 2 year old Ubuntu. I own 2 XTX cards but I'm actually switching back to NVIDIA on my main workstation for that reason alone. GPUs shouldn't be choosing winners in the OS world. The lack of a profiler is also a source of frustration. I think the smart thing to do is to develop on NVIDIA and then distribute to AMD. I hope things change though and I plan to continue doing everything I can do to support AMD since I badly want to see more balance in this space.

The compilation toolchain may be reliable but then you get kernel panics at runtime.

I've heard geohot is upset about that. I haven't tortured any of my AMD cards enough to run into that issue yet. Do you know how to make it happen?

Last time I used AMD GPUs for GPGPU all it took was running hashcat to make the desktop rendering unstable. I'm sure leaving it run overnight would've gotten me a system crash.

That's always happened with NVIDIA on Linux too, because Linux is an operating system that actually gives you the resources you ask for. Consider using a separate video card that's dedicated to your video needs. Otherwise you should use MacOS or Windows. It's 10x slower at building code. But I can fork bomb it while training a model and Netflix won't skip a frame. Yes I've actually done this.