https://www.youtube.com/watch?v=cqshaJTI8FQ
I have never had any success with OC with GPUs. I googled and read so many methods. All ended up with me just sticking with the factory settings in the end. This video made it simple enough for me, and it works. He tackles it from the goal of improving gaming, but it works for crunching too.
His first section is messing with two video settings in the Nvidia control panel. Not sure if it helps with headless crunchers, but it does help the benchmarks a bit.
His second section is where I needed the help. How to use MSI afterburner, without making everything crash. 1) fan settings. 2) unlock the necessary settings. 3) max three sliders without fear. 4) push two sliders to each of the value he says. Done!
This worked for me with a 1080 ti and three 1660 Tis. GPU-Z shows faster clock speeds and they all seem to be stable. Looking forward to improved credits. Probably worse electric bill though.
Now, if there was something similar for AMD VII...