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.

I thought I'd share a bit more information here, which possibly answers my own question! The SP3 I've been using up until now is a machine for work, so has been upgraded to Windows 8.1 Enterprise and uses, among other things, DirectAccess for connection to our office. I've now got myself a second SP3 for home use which has not been "updated" by our IT department. This one appears to show significantly better performance during "sleep". So far, for example, there are always bits showing in the 32s "DRIPS" buckets and the batter drain per sleep period is minimal (with most sleep periods showing as either "green" or "amber" in the sleep study). So, based on this, it seems clear that my work unit is misbehaving - the questions then become "why" and "how can I stop it". Is there any way one can dig into more detail on exactly what could be causing my USB and graphics devices to be active so much during sleep?

Interestingly, last night was one of the first times I've seen an InstantGo session which didn't include the USB xHCI Compliant Host Controller (but it did include the HD Graphics at 100% activation and in 4 hours I lost 16% of my battery). If anyone is interested, my latest sleep study report can be seen at http://1drv.ms/1s1KZud.

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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82 answers

Anonymous

2014-07-14T08:15:06+00:00

I thought I'd share a bit more information here, which possibly answers my own question!

The SP3 I've been using up until now is a machine for work, so has been upgraded to Windows 8.1 Enterprise and uses, among other things, DirectAccess for connection to our office.

I've now got myself a second SP3 for home use which has not been "updated" by our IT department. This one appears to show significantly better performance during "sleep". So far, for example, there are always bits showing in the 32s "DRIPS" buckets and the batter drain per sleep period is minimal (with most sleep periods showing as either "green" or "amber" in the sleep study).

So, based on this, it seems clear that my work unit is misbehaving - the questions then become "why" and "how can I stop it".

Is there any way one can dig into more detail on exactly what could be causing my USB and graphics devices to be active so much during sleep?
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Anonymous

2014-07-03T09:24:34+00:00

Interestingly, last night was one of the first times I've seen an InstantGo session which didn't include the USB xHCI Compliant Host Controller (but it did include the HD Graphics at 100% activation and in 4 hours I lost 16% of my battery).

If anyone is interested, my latest sleep study report can be seen at http://1drv.ms/1s1KZud.
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