The official solution will be to have Open Image Denoise working on GPU: OIDN support Intel, NVIDIA, and AMD GPUs
I can’t wait for it, even if I use an Nvidia GPU, as OIDN and Optix differ like night and day.
A solution that I sometimes use when I want a better denoiser in the viewport is to enable OIDN but set it to start only at like 50 or 100 samples. In this way, I can move swiftly around, and then when I let the viewport “rest”, OIDN can kick in.