I'm interested to know what other users tend to see when running the "powercfg /sleepstudy" tool on their Surface Pro 3s (as per http://blogs.windows.com/windows/b/windowsexperience/archive/2014/06/26/sleep-study-diagnose-what-s-draining-your-battery-while-the-system-sleeps.aspx ). I'm finding that all my "InstantGo" sessions have a drain rate of between 1200 and 2200mW, which can correspond to between 10% and 20% of the battery drain in the 4 hours before the machine hibernates. Looking at the culprits, almost all the sessions show the following device running for the entire "sleep" period: USB xHCI Compliant Host Controller (\_SB.PCI0.XHC) Fx Device 100% 4:00:00 Is this expected? FWIW, I tend to leave the keyboard cover connected during sleep. Sometimes (when the drain is at the high end of the range), I also see the following: Intel(R) HD Graphics Family (\_SB.PCI0.GFX0) Fx Device 100% 4:00:00 Interestingly, during the first few days I had the SP3, the graphics driver was appearing in every session of the sleep study report. More recently, though, it has stopped appearing. Recently I've been leaving the Surface at the start screen rather than the Desktop, so this may be related - is there a recommendation about coming out of the Desktop before going to "sleep" I also never see anything in the "DRIPS histogram" - should I? What are other people seeing? On a related note, does anyone know if there is a way of changing the time before the machine hibernates? For me, 2 hours (or even 1 hour) would probably be fine - if I'm actively going from one office to another, then the "instant" resume is great, but if I'm at home, leaving the machine for a while, then 4 hours is overkill.

Are you running standard Win 8.1 Pro, or Windows 8.1 Enterprise? As I say, I'm nervous about trying a refresh, but maybe uninstalling/reinstalling the xHCI driver might be a good start for me...

Nope .. even with Skype running it is not draining any battery during sleep. So there must have been a confound there. I'm happy that now it works properly but it is kinda frustrating not knowing what was causing the problem.

I put it into sleep without skype last night, and it did not even lose 1% during 4 hour sleep before it hibernated. Sleepstudy reports all green. Also it did not lose any battery during 1hr 30min sleep in the morning. I just turn on the skype and put it into sleep, so I will let you know what happens in a couple of hours.

Interesting stuff... I'm don't think desktop Skype can be the only culprit, sadly, as I didn't have it installed until very recently (yet still saw the xHCI controller issue). That said, I do have VoIP phone software installed - I wonder whether there could be some interaction with the camera and/or headset which is causing the problem. I'm wary of going down the refresh route (not least as this is a corporate PC, reinstalled with Windows Enterprise so I'm not even sure if a refresh is possible). It'll be interesting if your probably comes back or goes away, though. FWIW - before I left work on Friday, I rebooted the machine and then put it straight into sleep (after, admittedly, both Skype and my VoIP app had started). I lost only 10% over the weekend (but, again, the culrprit was the xHCI controller running for 100% of the sleep time). I'll try again tonight, but without starting the VoIP app, or Skype.

I might have found the culprit .. it seems like when I have Skype (desktop) running during the connected standbay, it drains a lot of battery with USB xHCI Compliant Host Controller (\_SB.PCI0.XHC) being active 100%. I just closed Skype and put it to sleep, and it was fine. I'm not 100% sure, but I will try several more times and report.

What should "sleepstudy" show for a Surface Pro 3

Anonymous

I'm interested to know what other users tend to see when running the "powercfg /sleepstudy" tool on their Surface Pro 3s (as per http://blogs.windows.com/windows/b/windowsexperience/archive/2014/06/26/sleep-study-diagnose-what-s-draining-your-battery-while-the-system-sleeps.aspx).

I'm finding that all my "InstantGo" sessions have a drain rate of between 1200 and 2200mW, which can correspond to between 10% and 20% of the battery drain in the 4 hours before the machine hibernates.

Looking at the culprits, almost all the sessions show the following device running for the entire "sleep" period:

USB xHCI Compliant Host Controller (\_SB.PCI0.XHC)	Fx Device	100%	4:00:00

Is this expected? FWIW, I tend to leave the keyboard cover connected during sleep.

Sometimes (when the drain is at the high end of the range), I also see the following:

Intel(R) HD Graphics Family (\_SB.PCI0.GFX0)	Fx Device	100%	4:00:00

Interestingly, during the first few days I had the SP3, the graphics driver was appearing in every session of the sleep study report. More recently, though, it has stopped appearing. Recently I've been leaving the Surface at the start screen rather than the Desktop, so this may be related - is there a recommendation about coming out of the Desktop before going to "sleep"

I also never see anything in the "DRIPS histogram" - should I?

What are other people seeing?

On a related note, does anyone know if there is a way of changing the time before the machine hibernates? For me, 2 hours (or even 1 hour) would probably be fine - if I'm actively going from one office to another, then the "instant" resume is great, but if I'm at home, leaving the machine for a while, then 4 hours is overkill.

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Anonymous

2014-10-06T16:55:44+00:00

Are you running standard Win 8.1 Pro, or Windows 8.1 Enterprise?

As I say, I'm nervous about trying a refresh, but maybe uninstalling/reinstalling the xHCI driver might be a good start for me...
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Anonymous

2014-10-06T16:20:32+00:00

Nope .. even with Skype running it is not draining any battery during sleep. So there must have been a confound there. I'm happy that now it works properly but it is kinda frustrating not knowing what was causing the problem.
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Anonymous

2014-10-06T14:44:35+00:00

I put it into sleep without skype last night, and it did not even lose 1% during 4 hour sleep before it hibernated. Sleepstudy reports all green. Also it did not lose any battery during 1hr 30min sleep in the morning.

I just turn on the skype and put it into sleep, so I will let you know what happens in a couple of hours.
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Anonymous

2014-10-06T07:54:11+00:00

Interesting stuff...

I'm don't think desktop Skype can be the only culprit, sadly, as I didn't have it installed until very recently (yet still saw the xHCI controller issue). That said, I do have VoIP phone software installed - I wonder whether there could be some interaction with the camera and/or headset which is causing the problem.

I'm wary of going down the refresh route (not least as this is a corporate PC, reinstalled with Windows Enterprise so I'm not even sure if a refresh is possible). It'll be interesting if your probably comes back or goes away, though.

FWIW - before I left work on Friday, I rebooted the machine and then put it straight into sleep (after, admittedly, both Skype and my VoIP app had started). I lost only 10% over the weekend (but, again, the culrprit was the xHCI controller running for 100% of the sleep time).

I'll try again tonight, but without starting the VoIP app, or Skype.
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Anonymous

2014-10-05T19:07:55+00:00

I might have found the culprit .. it seems like when I have Skype (desktop) running during the connected standbay, it drains a lot of battery with USB xHCI Compliant Host Controller (\_SB.PCI0.XHC) being active 100%. I just closed Skype and put it to sleep, and it was fine. I'm not 100% sure, but I will try several more times and report.
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