In unbiased engines, you just  need to define your max count of samples, and that's all there is.

Max samples is how many Octane will throw til the image is clean.

Octane settings Kernal tab:

Max samples: adjust with ipr window (square with plus sign in it, at the top of Live Viewer).

Caustic blur: 0.2
GI Clamp: 2.

Path term. power: 0.5

Parallel samples: turn all the way up

Check Adaptive sampling
Noise Threshold 0.04