this is something else. IRST was Intel custom implementation, back when S0 did not exist. It required a custom partition. IIRC, suspend to disk when battery ru

this is something else. IRST was Intel custom implementation, back when S0 did not exist. It required a custom partition. IIRC, suspend to disk when battery runs out is now one of the standard S0 features. At the OS level (windows 10) there is a telemetry to check the depletion rate, and initiate suspend to disk when the rate is too high or battery is too low. Check the logs made by microsoft powercfg, they are very informative and will help you reach power savings close to what S3 allowed. But I need that to work in Linux too, and last time I checked it wasn't as good.