Reading over traffic at TenForums, I came across a topic that pops up regularly. In Windows 10, the term “sleep” covers a number of states during which a PC reduces activity. In fact, according to the Windows Docs on System Power States, 7 such states are recognized. There are 6 ACPI power states and a “mechanical off” state (caused when a shutdown operation also turns off the PC’s power supply). “Why is sleep a regular TenForums topic?” you ask. “Good question!” Proper sleep on a Windows PC requires the right settings and drivers, one or both of which often get bollixed. And that, dear readers, is why Win10 Sleep issues make Sleepstudy worthwhile.
When it comes to most things sleep-related in Win10, the Powercfg command is a great source of information. This text block comes from the head of its Sleepstudy report.
Why Do Win10 Sleep Issues Make Sleepstudy Worthwhile?
It turns out that in Windows 10, sleep issues are best researched from the command line, using the powercfg (power configuration) command. It works with equal facility in an administrative command prompt or PowerShell session. This command covers a lot of capabilities and possibilities that I won’t get into here. Instead, I’ll recommend that those interested in learning more about this powerful and useful command (outside of sleep stuff) consult the Microsoft Docs page entitled “Powercfg command-line options.” It’s my go-to reference, too, so it comes highly recommended.
In reading over a recent tale of Win10 sleep woe, the original poster (OP) at TenForums indicated he’d tried two variants on powercfg that ended up not telling him much (or anything useful) about recent sleep activity. Those commands were
The /requests option simply enumerates application and driver Power Requests, usually to initiate or interrupt one or more of the Windows sleep states. The /lastwake option reports on what service of type of wake request caused the system to most recently wake up from a sleep state. The OP’s basic complaint was that neither of these commands was telling him anything useful. Nothing loath to try it myself, I ran those commands and saw nothing terribly useful from them either, to wit:
Upon running the cited commands, they didn’t tell me much of anything, either.
In my case, I knew /lastwake wouldn’t tell me much because I’d installed a new Start10 version earlier this morning. It requires a reboot to finish up its update process, so that meant there was no last wake-up to report. As far as the /requests option goes, I didn’t know what to expect, never having used it before. Good thing I had no expectations, because it enumerated “None” for all the various wake/sleep requests it tracks.
Where Does Sleepstudy Come Into Play?
But there’s more to Powercfg than just a bunch of individual query options. In fact, the Sleepstudy option generates an entire HTML-formatted report on system power state transitions, which include sleep, hybrid sleep, hibernation, and shutdowns. By default the report is named sleepstudy-report.html and it resides in the %windir%\System32 folder (on my — and most — Win10 PCs, that means it lives in C:\Windows\System32). You can double-click this file to open it in your default browser. All screen caps I show from this recently-produced file come from Edge.
Power State Transitions and Durations
Right away, I noticed a very useful table near the head of the Sleep Study file. Here’s what it looks like from my production PC:
Notice the various states shown of which “Standby (Hybrid)” represents a sleep state on my PC.
[Notes: I truncated the table to omit empty fields; Click image for full-sized view.]
The table is pretty easy to read. It shows start times (far left) and duration (left 2nd) for each state documented. The rhythm on my system is pretty simple and consists mostly of transitions from active [in use/awake] to standby (hybrid) [asleep], with a single reboot this morning after I’d installed the aforementioned Start10 update. Easy-peasey, right? That’s what the OP from the TF post could (and probably should) have used to get more info on recent sleep activity on his PC, too.
If you read down further into the file, you’ll see a set of “Analysis Results” for each state transition documented in the preceding table. This, too, provides useful information about what happened to get a PC into (and out of) some specific power state mentioned in the table. Overall, this is good and helpful information, well worth consulting when researching a PC’s power state transitions. Please think of it the next time you’re curious (or troubleshooting) Windows 10 sleep issues. Great stuff!