Suspend to disk - aka Apple Save Sleep - doesn't work in Big Sur

Question

Since installing Big Sur on my MacBook Air 2014, I noticed that suspend to disk doesn't seem to work anymore. Suspend to disk (or Safe Sleep as Apple calls it) should be activated after an hour into Suspend to RAM (I think).

Searching around a little bit, it seems that pmset is the tool for it. This is the output of pmset -g:

System-wide power settings:
Currently in use:
 standbydelaylow      10800
 standby              1
 halfdim              1
 hibernatefile        /var/vm/sleepimage
 powernap             0
 gpuswitch            2
 disksleep            10
 standbydelayhigh     86400
 sleep                1
 autopoweroffdelay    259200
 hibernatemode        3
 autopoweroff         1
 ttyskeepawake        1
 displaysleep         15
 highstandbythreshold 50
 acwake               0
 lidwake              1

The documentation (man pmset) for autopoweroff is:

autopoweroffdelay specifies the delay, in seconds, before entering autopoweroff mode.

259200 seconds is 3 days! No wonder that my battery is empty when I open it up after some days. I think this should be set to about an hour (3600). I've never fiddled with pmset before. Is it save to do this?

More importantly, what could be the reason for this to be set to such a high value? I'm pretty sure this was set to about an hour in earlier versions of MacOS.

Answer 1

sudo pmset autopoweroffdelay 3600 did the trick, suspend to disk works again.

What I still don't understand is way this was set to such an absurdly high value in the first place. The only reason I can imagine is that suspend to RAM got very efficient with the new M1 architecture; making suspend to disk obsolete. Forcing this on older Macs though seems very questionable.