Having this issue from Windows 10 in Even Viewer there are annoying events saying:
The speed of processor 0 in group 0 is being limited by system firmware. The processor has been in this reduced performance state for 71 seconds since the last report.
The speed of processor 2 in group 0 is being limited by system firmware. The processor has been in this reduced performance state for 71 seconds since the last report.
The speed of processor 3 in group 0 is being limited by system firmware. The processor has been in this reduced performance state for 71 seconds since the last report.
The speed of processor 1 in group 0 is being limited by system firmware. The processor has been in this reduced performance state for 71 seconds since the last report.
I am on Windows 8.1, I was in Windows 10 but it has too many driver issues and stuff so I factory restored, and still this event happens. Have the latest BIOS: BIOS Version/Date Insyde F.42, 18/03/2015 SMBIOS Version 2.8
I had to factory restore again an hour ago since the factory restore wasn't a full one.

- <Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event">
- <System>
<Provider Name="Microsoft-Windows-Kernel-Processor-Power" Guid="{0F67E49F-FE51-4E9F-B490-6F2948CC6027}" />

<EventID>37</EventID>

<Version>0</Version>

<Level>3</Level>
+ System
- Provider
[ Name] Microsoft-Windows-Kernel-Processor-Power
[ Guid] {0F67E49F-FE51-4E9F-B490-6F2948CC6027}
EventID 37
Version 0
Level 3
Task 7
Opcode 0
Keywords 0x8000000000000000
- TimeCreated
[ SystemTime] 2015-11-01T18:41:50.175333100Z
EventRecordID 971
Correlation
- Execution
[ ProcessID] 4
[ ThreadID] 192
Channel System
Computer WIN-7QBLL5R5M6C
- Security
[ UserID] S-1-5-18

- EventData
Group 0
Number 1
CapDurationInSeconds 71
PpcChanges 1
TpcChanges 0
PccChanges 0