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.

OK, well when you put it like that, it does sound like it's the USB controller. Though it's strange that it doesn't appear to be the root cause for everyone. After raising the issue with Microsoft, I was told it was a known issue from last year, but they never rolled a firmware update out then due to stability concerns. They have told me that they are now releasing it Jan 13th-14th this year. So I guess we'll wait and see.

around 98% in LPS during a normal sleep. if the usb xHCI error occored, then 0% in LPS.

Thanks, that's interesting. How much time does your unit spend in Low Power State?

In my case, a normal 4-hour sleep on SP3 tends to consume 3%-5% of the battery. However, if the " USB xHCI Compliant Host Controller (\_SB.PCI0.XHC)" is being activated forcibly by some incompatible desktop applications, the 4-hour battery drain will shot up to 11% or more. Some of the incompatible desktop applications I have noticed include: Kensington Trackball " TrackballWorks 1.2" Driver Google Chrome when visiting some flash-enabled websites.

Screenshot attached. Notice the battery drain of up to 3500mW!

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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82 answers

Anonymous

2015-01-02T14:36:01+00:00

OK, well when you put it like that, it does sound like it's the USB controller. Though it's strange that it doesn't appear to be the root cause for everyone.

After raising the issue with Microsoft, I was told it was a known issue from last year, but they never rolled a firmware update out then due to stability concerns. They have told me that they are now releasing it Jan 13th-14th this year.

So I guess we'll wait and see.
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Anonymous

2015-01-02T00:59:48+00:00

around 98% in LPS during a normal sleep. if the usb xHCI error occored, then 0% in LPS.
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Anonymous

2015-01-01T23:54:03+00:00

Thanks, that's interesting. How much time does your unit spend in Low Power State?
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Anonymous

2015-01-01T11:41:45+00:00

In my case, a normal 4-hour sleep on SP3 tends to consume 3%-5% of the battery. However, if the " USB xHCI Compliant Host Controller (\_SB.PCI0.XHC)" is being activated forcibly by some incompatible desktop applications, the 4-hour battery drain will shot up to 11% or more.

Some of the incompatible desktop applications I have noticed include:

Kensington Trackball " TrackballWorks 1.2" Driver

Google Chrome when visiting some flash-enabled websites.
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Anonymous

2015-01-01T11:32:02+00:00

Screenshot attached. Notice the battery drain of up to 3500mW!
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