Surface pro 4 - clock speed of CPU keeps the same

I've been looking into this, and here's what I found out:

 There is a technology called "Intel Speed Shift". In a computer, the OS tells the processor to speed up or slow down depending on current needs. Intel Speed Shift turns control of that over to the processor, and as a result everything is quicker (and theoretically can save a small amount of battery life).

 Intel Speed Shift came out in November of last year, but is only now being "turned on" by Windows. "Processor Performance Autonomous Mode" is the on / off switch for Intel Speed Shift.

THEORY:

 One of two things is probably happening on our Surface devices.

1. Intel Speed Shift is causing the OS to report an incorrect processor speed. Since many CPU diagnostic programs read the speed from the OS, they are also misreporting it. This may be supported by the fact our fans are not running constantly and battery life is nearly the same as it was before the update.

OR

2. Intel Speed Shift, or it's connection with Windows, is flawed and causes our CPUs to run too fast.

 Therefore, if you apply one of the registry fixes you are merely turning off Intel Speed Shift. This turns control of the CPU back over to Windows and things run as before. Alternately, you can leave it on and wait for a patch to allow Intel Speed Shift and Windows to work together properly.

Personally, since I'm not noticing dramatic heat or battery use increases, I'm waiting a bit to see how MS may update the integration of Intel Speed Shift.

For fun - here are some of the new Win 10 power processor settings:

8baa4a8a-14c6-4451-8e8b-14bdbd197537 – Processor performance autonomous mode (Enable/Disable)

Specify whether processors should autonomously determine their target performance state.

36687f9e-e3a5-4dbf-b1dc-15eb381c6863 – Processor energy performance preference policy (Percent)

Specify how much processors should favor energy savings over performance when operating in autonomous mode.

cfeda3d0-7697-4566-a922-a9086cd49dfa – Processor autonomous activity window (Microseconds)

Specify the time period over which to observe processor utilization when operating in autonomous mode.

4e4450b3-6179-4e91-b8f1-5bb9938f81a1 – Processor duty cycling

Specify whether the processor may use duty cycling

More fun if you're a tech person: http://www.anandtech.com/show/9582/intel-skylake-mobile-desktop-launch-architecture-analysis/7

Go to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Power

Change CsEnabled to 0 (should be previously 1)

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Power\PowerSettings\54533251-82be-4824-96c1-47b60b740d00\8baa4a8a-14c6-4451-8e8b-14bdbd197537

Change Attributes to 0 (should be previously 1)

Restart and now you should have advanced power settings visible in Power Options > Change Advanced Power Settings. Under Processor Power Management you should now see Processor performance autonomous mode. This should be originally Enabled so change to Disabled.

This definitely seems to work, but what exactly is "Processor performance autonomous mode" and why is it enabled in the first place?  Google doesn't really come up with anything useful.

For those who have applied the registry fix and deemed the issue solved, have you notice any improvements in battery life? After the AU, my SP4 is still getting horrible battery life. Is it too much to ask for a better battery life on this device without resorting to battery saver mode, lowest brightness, wifi off, location and etc.....

I'm getting around 4-5 hours of battery life on my SP4 i7/8/256, which I think is around the same as it was before the registry fix. Unfortunately the AU wiped the battery stats, so I don't really know whether this is worse than pre-AU, but I suspect that it is.

It seems a regedit issue, I got an experimental fix from here(https://www.reddit.com/r/Surface/comments/4wfish/progressfix\_for\_the\_anniversary\_update\_cpu/) and it works fine until now, mine is surface book i5/dgpu/256g, hope it works for you

For those who have applied the registry fix and deemed the issue solved, have you notice any improvements in battery life? After the AU, my SP4 is still getting horrible battery life. Is it too much to ask for a better battery life on this device without resorting to battery saver mode, lowest brightness, wifi off, location and etc.....