System: Various. Specific to Xorg only, no desktop manager -- just X.
Defaults for X are 10 min for blanking (usually set by the setterm command -- and the default is 10 min), 20 min for blanking (set by the X11 server).
Question: Is there a way in the global config file to disble the 20 min timeout?
by the way: xset s off doesn't get it.