The karma help about sampling has all this stuff about variance and uniform pixel oracle where are those settings in H20? Is there no noise threshold for sampling?

In H20, open a lopnet, put down a "Karma" (that creates a Karma rendersettings lop and a USD render ROP), on the Karma rendersettings LOP go to the Advanced Tab and there the Sampling sub-tab. There you will find the settings.

Note: This is KarmaCPU only. KarmaXPU does not have this.