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.

A couple of things to report. I just tested my wife's Surface Pro 3 with i5 processor, and again the Skype was the culprit, she had USB xHCI Compliant Host Controller (\_SB.PCI0.XHC) active 100% of time during sleep and battery got drained 11% during 4 hour sleep. After quitting Skype, 0%. Another thing is that with recent update, I cannot do sleepstudy with powercfg anymore - I'm not sure what is going on. It says The Power Efficiency Diagnostic library (energy.dll) could not be loaded when I do > powercfg sleepstudy. As you say, it looks like Skype (or, I think, more generally, comms apps which perhaps use the headset of camera - remember, I was seeing this xHCI problem before I'd even installed Skype) are the killers. So, is this something which MS needs to address in the Surface drivers, or is it something application writers need to fix (which, of course, in Skype's case, is MS!)? Either way, how do we draw more attention to it, so that someone with power to fix it takes an interest? FWIW - I can still do a sleepstudy (and believe I'm up to date with updates).

A couple of things to report. I just tested my wife's Surface Pro 3 with i5 processor, and again the Skype was the culprit, she had USB xHCI Compliant Host Controller (\_SB.PCI0.XHC) active 100% of time during sleep and battery got drained 11% during 4 hour sleep. After quitting Skype, 0%. Another thing is that with recent update, I cannot do sleepstudy with powercfg anymore - I'm not sure what is going on. It says The Power Efficiency Diagnostic library (energy.dll) could not be loaded when I do > powercfg sleepstudy.

:) Hopefully it gets fixed soon!

That is a fair point and I am jealous! I do see something nearer the 400mW on the SP3 I have at home, but with the work one I started off losing about 20% over 4 hours, so getting that to 10% is definitely a step in the right direction!

I'm glad it is improving for you. But 904mW discharge rate is still very high. My discharge rate when everything is green is about 136mW, and I lose barely 1% of battery during 4 hour sleep before it hibernates.

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.

Locked Question. This question was migrated from the Microsoft Support Community. You can vote on whether it's helpful, but you can't add comments or replies or follow the question.

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Anonymous

2014-10-24T08:09:18+00:00

A couple of things to report. I just tested my wife's Surface Pro 3 with i5 processor, and again the Skype was the culprit, she had USB xHCI Compliant Host Controller (\_SB.PCI0.XHC) active 100% of time during sleep and battery got drained 11% during 4 hour sleep. After quitting Skype, 0%.

Another thing is that with recent update, I cannot do sleepstudy with powercfg anymore - I'm not sure what is going on. It says The Power Efficiency Diagnostic library (energy.dll) could not be loaded when I do > powercfg sleepstudy.

As you say, it looks like Skype (or, I think, more generally, comms apps which perhaps use the headset of camera - remember, I was seeing this xHCI problem before I'd even installed Skype) are the killers.

So, is this something which MS needs to address in the Surface drivers, or is it something application writers need to fix (which, of course, in Skype's case, is MS!)? Either way, how do we draw more attention to it, so that someone with power to fix it takes an interest?

FWIW - I can still do a sleepstudy (and believe I'm up to date with updates).
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Anonymous

2014-10-24T07:49:55+00:00

A couple of things to report. I just tested my wife's Surface Pro 3 with i5 processor, and again the Skype was the culprit, she had USB xHCI Compliant Host Controller (\_SB.PCI0.XHC) active 100% of time during sleep and battery got drained 11% during 4 hour sleep. After quitting Skype, 0%.

Another thing is that with recent update, I cannot do sleepstudy with powercfg anymore - I'm not sure what is going on. It says The Power Efficiency Diagnostic library (energy.dll) could not be loaded when I do > powercfg sleepstudy.
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Anonymous

2014-10-08T15:12:40+00:00

:) Hopefully it gets fixed soon!
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Anonymous

2014-10-08T14:52:56+00:00

That is a fair point and I am jealous! I do see something nearer the 400mW on the SP3 I have at home, but with the work one I started off losing about 20% over 4 hours, so getting that to 10% is definitely a step in the right direction!
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Anonymous

2014-10-08T13:49:21+00:00

I'm glad it is improving for you. But 904mW discharge rate is still very high. My discharge rate when everything is green is about 136mW, and I lose barely 1% of battery during 4 hour sleep before it hibernates.
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