[Egon]

...I don't know how to go back into settings with a cosole.

Along with the resources that TB pointed you at, you should be able to bring back the settings by invoking the executable with the "-configonly" option:

./FAH504-Linux.exe -configonly

I don't think the Linux version has an option to set the percentage for processor use, though. I'd use the top command to see what's using your processor. If you're only folding at around 80% or so, I'm betting that you have some other process (or two) that's consistently using the other 20%.

[Clara Lou]

I opened KsysGuard performance monitor, and, aside from FAH, Firefox is the biggest user, at about 4% now and then. Occasionally, something else will use up to 2%. I can't identify any other user.
The only reason that I care is that my processor isn't very fast. I hate to be using only 80%.