Question Processor working with only half performance

[Joohny]

Hi, guys. Can someone help me to solve a problem that is happening on my pc?
I have a AMD A4-6300, with 6gb ddr3 ram and a motherboard asrock fm2a88x extreme4+ running Windows 8.1. It's a basic pc just for youtube and some indie games.
The processor has the frequency of 3,69Ghz on full use, but some days ago, sudenly when i turn on the pc i noticed in task manager the processor locked in the frequency 1.76Ghz while on full use. And it doesn't matter if i try to do a stress test, the frequency don't go to the maximum, just keep stuck in 1.76Ghz.
Looking on CPUz, i noticed that the vcore of the processor is only half of the value who was before this problem. Before was 1.4v and now is only 0.9v.
I've alrealdy tried to reset bios, upgrade, downgrade, test in other windows in dual boot ( win8, 10 and even 7, still the same) and nothing change.
Tried to do some tricks that i find it on internet, like change some registry keys, and nothing resolves.
I'll post here a link to a screenshoot of cpuz with a comparison.

https://ibb.co/gMC6pnB

Someone have some idea of what is happening?
Thanks!

(My english is not good, i hope i was understandable)

 

[CountMike]

Check Power options, if Maximum processor state is less than 100%, CPU will work at only base frequency with no boost.

 

[Joohny]

It's on maximum. I've tried to change de power plan to see if something happens and keeps the same.
I've tried yesterday to do a overclock and the vcore of the processor didn't change, always keep on 0.9v.
I starting to think that there's a problem with the motherboard or the processor.

 

[Amosis]

It's on maximum. I've tried to change de power plan to see if something happens and keeps the same.
I've tried yesterday to do a overclock and the vcore of the processor didn't change, always keep on 0.9v.
I starting to think that there's a problem with the motherboard or the processor.

I don't know if you have fixed this yet but my CPU was running at 0.97ghz So follow this path in your registry.
Computer\HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\AmdPPM
If it's an intel processor it will be IntelPPM not AmdPPM
Double click on Start in the right panel and change the value data to 1 Reboot your computer and you should be good to go.
That said. In my other computer it's set to 3

 

[Joohny]

I've already did this change, but in my case, the value was 4. But, the performance keeps the same. In task manager really shows using the maximum Ghz, but when i open any program of benchmark or cpu info like cpuz, keeps showing the real ghz, in my case 1,7ghz.
I have no more ideas of what to do, to be honest. I think i will just give up.