I’m dealing with a lot of fireflies in my scene in 3DMax. I did change the AA value nothing worked. High Render Quality denoising only leads to fireflies, nor Nvidia or Intel.
I use Corona Sky as Env but even with HDRI, the fireflies get more!!! I have nightmares at night about Fireflies now 
LightMix value are not higher than 1, and when sky is only visible, it only generates the fireflies..
For how long are you rendering your image? (how many passes)
If you are still getting fireflies after ~50 passes, that could mean that your scene is built with some kind of mistake. It could be a highly reflective surface reflecting some strong light, a light with too high intensity, LightMix, or many other things. You can check some troubleshooting ideas here: https://support.chaos.com/hc/en-us/articles/4528247036305-How-to-get-rid-of-excessive-noise
If you are unable to find the root of the issue by yourself, please send us a support ticket and attach your scene to it (archived with all assets): https://support.chaos.com/hc/en-us/requests/new
