I've been using the Denoise node in the compositor, hooked up to Denoising Normal/Albedo, with those render denoising passes turned on. Works fine. I believe that's the OpenImage denoise algorithm.
In latest 2.91 nightlies, I see in the Scene settings under Denoising, a Render option with choices NLM and OpenImageDenoise.
How are these related? Are they the same? If I keep my denoise node in the compositor and turn on the Scene-settings denoise do I get two denoise passes? If I choose NLM in the settings, what happens to the denoise node in the compositor? Should I just remove the compositor nodes?
I see in this commit the new text explaining that the denoise passes are adapted to the selected denoiser, but that doesn't say anything about what you need in the compositor.
And finally, is OpenImageDenoise or NLM better?