Hi.
Unfortunately, someone has spread all over the internet a not optimal node configuration that can make you not getting the best result in many scenes.
This is the simplest configuration:
But there are even better configurations. You read starting from here:
https://blenderartists.org/t/intel-open-image-denoise-released-for-2-81/1144893/115
And all this thread:
https://blenderartists.org/t/big-denoise-test-intel-open-image-denoise-vs-others
Here LordOdin node setup (Uses a lot of RAM until devs can solve the problem)
https://blenderartists.org/t/big-denoise-test-intel-open-image-denoise-vs-others/1175114/53
Edit:
I am not sure about whether it is convenient to use Image or Noisy image output. I’ve seen some having artifacts with Noisy Image output.