I'm going to investigate thist stuff tomorrow, but I wanted to ask about my main usage case. I have an OjPi PC running a chess engine 24/7 on two cores atm, but could use 4 soon. Anyway, it does a LOT of idling, so I'd like to reduce power there if possible, but obviously when a game starts, it can require 100% DRAM and CPU for long periods. It doesn't think during the opening, and occasionally (due to the nature of chess engines) it is unable to come up with a move to ponder while waiting for the opponent. So it does sometimes go back to idle during a game, just not for long.
I don't think a cron solution for DRAM will work in this scenario, but clearly reducing DRAM speed is desirable if it can kick back up when needed. I don't need any USB ports active, though it's in a location where it's rarely useful to use the box for fdisk or a TTL connection via screen. HDMI is off, but I don't think it's done in the fex file. It gets not much network activity, but relatively constant trickle.
What do you think?