I'm pretty sure there's no difference. It does seem to be pretty hard to turn the theoretical win into a practical one - the GPU kernel needs to be coded extrem

I'm pretty sure there's no difference. It does seem to be pretty hard to turn the theoretical win into a practical one - the GPU kernel needs to be coded extremely efficiently to match the underlying hardware. AFAIK it's only a win for 3x3 - maybe for one other size too. Originally Winograd wasn't supported by cuDNN on NVidia's Tensor Cores (matmul-specific hardware on more recentish GPUs), vs CUDA cores, but a Google search seems to indicate it can be done - not sure if that's in cuDNN though.