Surface pro 4 - clock speed of CPU keeps the same

CPU clicking / screeching / buzzing noise?

When I installed the Windows 10 Anniversary Update on my Surface Pro 4 i5 I noticed two big issues so I rolled it back.

The first was that the fan was on nearly all of the time which was probably due to the issue this thread is about.

The second was a clicking / screeching / buzzing noise from the CPU. I've heard this before and was able to resolve it with a registry edit which apparently prevented the CPU from entering certain "c-states" when idle. However, after the anniversary update this noise not only came back but was way louder and audible all the time, certainly not just when the CPU was not busy. In addition, applying the same registry edit that had previously fixed it had no effect after the anniversary update.

I'm wondering whether the two issues are related. Has anyone else noticed this weird noise from the CPU area (top right when facing the screen)? And have they found that the fix to correct the CPU scaling also fixed this noise?

Makes you wonder what Microsoft are playing at, how can such issues get through their "testing"?

I really want to re-install the anniversary update but not until I can be sure these issues are fixed.

Thanks,

Andrew

M3 stuck at 1.50 GHz. What a bunch of clowns. It makes you wonder why they have these insider previews with months of evaluation and still a major bug like this slips through. How can the Surface team not discover something like this before release? Unfathomable.

I've now installed the Windows 10 Anniversary Update again via normal Windows Updates and the CPU scaling issue appears to be fine now on my SP4 i5. I've checked it's still OK after a few restarts and whether it's on mains or battery power. There were some new 1511 updates installed first so that may have made the difference unless they have changed the anniversary update.

Edit: A day later and my i5 is stuck at 2.47 GHz again!

However, I'm still getting the very irritating clicking noise from the CPU area. It very briefly stops when you give the machine something to do but then appears again as soon as the machine is slightly less busy. The best way to describe it is as being like a mechanical hard disk. I'm sure it's far louder a noise than it was before the anniversary update which as I've mentioned I was able to stop with a registry setting preventing certain c-states. Again, this same registry setting no longer stops the noise. I'm going to start a separate thread about this noise.

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.