Fixed with today's update. Thanks, MS!
NOTE: I had to reboot twice after updating. So if anyone is not seeing the fix try a restart.
Surface pro 4 - clock speed of CPU keeps the same
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Anonymous
After updating to windows 10 (1607), I find that the clock speed of the CPU keeps to be 2.92GHz when plugged, and to be 2.47GHz when using battery. My surface pro 4 has a core i5 CPU. It seems strange because the clock speed of CPU should change with the workload in the Task Manager. Does anyone have the same problem?
Surface | Surface Pro | Display and screen
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Anonymous
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Anonymous
2016-08-21T16:30:45+00:00 Hi, this is really a good find and thank you for the clear explanation!
Which policy would you recommend best to adjust for a balance of both? I am still hopeful that somewhere and somehow MS will sort this out with an update next week and that the battery life will magically improve.
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Anonymous
2016-08-21T19:31:58+00:00 Actually, the culprit seems to be Microsoft using 0 as default value for "Processor energy performance preference policy". This tells your Speed Shift enabled Skylake CPU not to sacrifice performance for energy savings under any circumstances resulting in a permanent max turbo state. You can now either go back to the old supposedly inferior OS controlled P-states and disable Speed Shift by setting "Processor performance autonomous mode" to disabled
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Power\PowerSettings\54533251-82be-4824-96c1-47b60b740d00\8baa4a8a-14c6-4451-8e8b-14bdbd197537]
"Attributes"=dword:00000002
or let Speed Shift actually do its job by giving it a useful policy to work with
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Power\PowerSettings\54533251-82be-4824-96c1-47b60b740d00\36687f9e-e3a5-4dbf-b1dc-15eb381c6863]
"Attributes"=dword:00000002
If you set "Processor energy performance preference policy" to 50, you will see Speed Shift happily using anything from 0.5 GHz up to the max turbo frequency. By the way, 100 results in your CPU rarely exceeding 1.0 GHz.
The current default settings most likely just disable DVFS while still allowing cores to sleep in C7, which could explain battery life being similar in a light use scenario.
Best answer yet. This makes perfect sense. Super easy to implement and works like a charm.
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Anonymous
2016-08-21T19:51:30+00:00 Is it possible to summarize in easy to follow steps for the less technical amongst us, the proposed "solution", please
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Anonymous
2016-08-21T20:24:14+00:00 Is it possible to summarize in easy to follow steps for the less technical amongst us, the proposed "solution", please
- Wait for MS to address this, because everyone above is speculating and hasn't come up with a tested method that actually increases battery life.
I appreciate the work everyone is doing and I am eagerly reading this thread, but for the less technical among us, I am following step 1 until I see concrete evidence that a particular tweak increases battery life in a test environment. And keeping my charger handy. :-/