Is Strassen's algorithm actually used in practice? Oddly enough I find myself doing a lot of matrix multiplication recently. But I am just using cublasCgemm3mStridedBatched from Nvidia's cuBLAS library, and it doesn't appear to be public information how it's implemented. Does anyone know if it's actually using Strassen?

Basically the library described at:

https://developer.nvidia.com/blog/cublas-strided-batched-mat...

I am a bit not-sold-yet on the AlphaTensor stuff because in practice it often seems like shuffling the data around in GPU memory is more expensive than doing the actual multiplications. It takes longer to move values between regular GPU memory and shared memory than it does to do a multiply, right? So all these algorithms that are optimizing the number of arithmetic operations, it isn't even clear to me that they're optimizing the right thing, because they require that you shuffle your data around in weird ways, and they don't generally measure the number of "memory moves" that are needed.

That said, I would be happy to drop in a replacement for cublasCgemm3mStridedBatched and test out if it worked better for me! It doesn't seem like these new AlphaTensor matrix multiplication routines are available as plain old c/c++ libraries yet, though.