jeffbee 3 days ago

Isn't this form of suspend really just a crutch for poor sleep management? A sleeping, but running, system should run that way for a week or so.

  • toast0 3 days ago

    Suspend (to disk) is valuable in itself, separate from sleep.

    Everybody has preferences, but if I put a laptop in a bag, I want it suspended. Everything should be as it was when I left. Not doing whatever wakeups I might be happy with if it's sleeping on my desk.

    Also immensely valuable for desktops on UPS. Run for a while, then suspend until power comes back. The UPS battery will not run for very many minutes, even if there is very little load.

    • cnst 2 days ago

      > The UPS battery will not run for very many minutes, even if there is very little load.

      I thought the conversion from 12V to 120V isn't all that inefficient?

      The ratings provided by UPS vendors only specify the full load and half-load runtimes, yet the runtimes for quarter-load and lower, are actually quite decent, although sometimes hard to find officially.

      I think the only problem with a very low load might be that the UPS might simply turn itself off if it thinks that it's actually unloaded (if the suspend-to-memory were to consume way too little power).

      • toast0 a day ago

        Well, the post I was responding to was asking for a week. And electric outages in my area tend to either be seconds or several hours to a day or two. I don't think my UPSes would stay up for an hour with a 2-5w load and almost certainly not for 4 hours. If the power is out, and my generator doesn't kick on, sleep isn't going to do it, suspend (or shutdown) is needed.

        • cnst 21 hours ago

          I'm pretty certain any UPS in a working order should not have an issue staying for an hour at 5W load.

          A 5W load for an hour is just a 5Wh capacity. That's nothing. A 16in MacBook Pro has a 100Wh battery.

          Vertiv Liebert PST5-660MT120, rated 660VA/400W, retailing at $77 USD on Amazon, https://www.amazon.com/dp/B07BXZPF99, is supposed to last "2 min" at full load, "7 min" at half-load, per Amazon listing.

          However, looking closer at the specs in the listing's User Manual in PDF, https://m.media-amazon.com/images/I/B14RNuD0LXS.pdf:

            10% — 56;
            20% — 28;
            25% — 13;
            30% — 14;
            40% — 11;
            50% — 7.5;
            …
            100% — 2.
          
          But what's 10%? A 10% of 400W is 40W.

          A load of 4W would then be a load of 1% of capacity that would be like 560 minutes (9.33 hours) if we extrapolate.

          So, my guess is, at a 5W load, a device can easily last about 5 hours or more, on an average UPS that's in good working order.

          I think the biggest problem may be, that it'd be consuming less than 5W during sleep, and could be deemed as parasitic load, and thus the UPS could actually turn itself off, to avoid wasting the energy, thinking that it's unloaded.