Question Low CPU Clocks when mains adapter is plugged in to laptop ?

[Killermruc]

Hello everyone this is now my Second Laptop which is experiencing this issue.

A year ago my Acer Notebook had this issue that whenever i plugged in the AC adapter it would clock down to 0.5 GHZ that had a Ryzen 7 CPU. I now have a HP Laptop which has an i7-8750H and it has the same issue that whenever i plug in the ac adapter the clocks are limited to 0.79 GHZ and CPU usage is also Limited to 36%. as soon as i unplug the ac adapter the clocks jump up to 2.6 GHZ and the usage goes up to 100% (whilst running Cinebench). but as soon as i plug ac adapter in again it drops down immediately. I am also using the same OEM power adapter which worked fine before. I installed Windows 10 on this Laptop two days ago.

Ive seen that a lot of other people are experiencing this problem so i tried a couple of fixes but none worked.

I have tried:

Regedit intelppm:

View: https://www.youtube.com/watch?v=vqKsN7AKYhY


Powercfg reset and powerplan settings https://answers.microsoft.com/en-us/windows/forum/all/cpu-stuck-at-038-ghz-when-charger-is-plugged-i...

Throttle Stop disable PROCHOT https://forums.tomshardware.com/threads/cpu-speed-too-low-stucks-on-1200mhz-core-i7-3610qm.1644804/#...

Did a Bios Update

Tried to disable intel Speedstep in the Bios but there was no option for that

The biggest difference was when i changed the intelppm from 3 to 4 but that lead to the Cpu being stuck at the base clock (2.21Ghz) and it wouldn't clock up or down so i think it has to be a Windows issue / Driver issue since two Laptops with two diffrent CPUs are experiencing this issue.

I have a third laptop from MSI with a I7700HQ which also runs Windows 10 latest version but the CPU clock issue is not present on that device. The only similarities both notebooks have is that i have CRU (Custom Resolution Utility) installed and for the Ryzen system RMT (Renoir Mobile Tuner) and for the HP Throttle Stop. Keep in mind that i never ran throttle stop on the HP Machine when this issue popped up the first time i ran it was after it started this behavior. Since CRU and Throttle Stop are Standalone Programs.
I deleted the Directory and restarted the device but no change.



Plugged in

Unplugged

Edit:

I just Started CS2 whilst unplugged and the Same issue Occrus so it dosent matter if its plugged in or not!

Also Noticed this in HWinfo

https://flic.kr/p/2pDE8T2

Throttle Stop is Also Active

https://flic.kr/p/2pDEJz2

 

[Roland Of Gilead]

Hey there,

Have you been playing around with Windows power plans? Reset all power plans back to default.

Open up powershell, and copy and paste these codes, and simply press enter after each one:

Ultimate Performance : powercfg -duplicatescheme e9a42b02-d5df-448d-aa00-03f14749eb61High Performance : powercfg -duplicatescheme 8c5e7fda-e8bf-4a96-9a85-a6e23a8c635c
Balanced : powercfg -duplicatescheme 381b4222-f694-41f0-9685-ff5bb260df2e
Power saver : powercfg -duplicatescheme a1841308-3541-4fab-bc81-f71556f20b4a

Then test again, trying each of the power plans. Any difference?

It also looks like your system is throttling. You could try to change the PL1/PL2 values in TS. Maybe stick both of them up to 80w or so.

 

[uWebb429]

@Killermruc

Your laptop is using an embedded controller (EC) to enforce some low ball turbo power limits. ThrottleStop can only control the MSR and MMIO power limits. It has no ability to control the EC power limits.

Try removing the Intel Dynamic Tuning driver from the device manager and block Windows from reinstalling it. Search Google for this as I have never had to do this myself.

 

[Killermruc]

@Killermruc

Your laptop is using an embedded controller (EC) to enforce some low ball turbo power limits. ThrottleStop can only control the MSR and MMIO power limits. It has no ability to control the EC power limits.

Try removing the Intel Dynamic Tuning driver from the device manager and block Windows from reinstalling it. Search Google for this as I have never had to do this myself.

Does Windows ship standard with Intel Dynamic Tuning drivers because i also did a clean install and went through the setup without wifi so that it wouldnt download any drivers in the Background but as soon as i got into the Desktop it was at 0.79 on a fresh windows install.

What would the EC Power limits be? is that like a safety thing if the Power supply is faulty like giving to much power or to little ? idk maybe its broken i cannot find any other variable which could cause a problem.

Someone also send me their Throttle stop config and i copied it one to one but it made no change i just cannot get it to boost while AC is plugged in. I ran Cinebench on the battery and it gave me a close enough score to other CPUs (i7 8750H) but as soon as the AC is plugged in the GHz just drop. I also took the machine apart an unplugged the battery and CMOS battery for half the day thinking it would reset something but no change. I also applied new thermal paste to the CPU and GPU but it wasn't overheating before so it made no difference.

 

[Killermruc]

Hey there,

Have you been playing around with Windows power plans? Reset all power plans back to default.

Open up powershell, and copy and paste these codes, and simply press enter after each one:

Ultimate Performance : powercfg -duplicatescheme e9a42b02-d5df-448d-aa00-03f14749eb61High Performance : powercfg -duplicatescheme 8c5e7fda-e8bf-4a96-9a85-a6e23a8c635c
Balanced : powercfg -duplicatescheme 381b4222-f694-41f0-9685-ff5bb260df2e
Power saver : powercfg -duplicatescheme a1841308-3541-4fab-bc81-f71556f20b4a

Then test again, trying each of the power plans. Any difference?

It also looks like your system is throttling. You could try to change the PL1/PL2 values in TS. Maybe stick both of them up to 80w or so.

Ive reset the PowerPlans and also Copied someone elses Throttle Stop config but still no difference

I also reinstalled Windows and went through the setup without Wifi so that it wouldnt download any drivers in the background but as soon as i got into the Desktop the CPU was at 0.79 GHZ.

 

[Killermruc]

Update

I did some more Testing and i Think i finally found the Root cause of this issue.

I charged the Laptop up to 100% unplugged it and wanted to play some GTA 4 relatively old game should run with ease. But as soon as i Loaded in the game i Realized that Nothing was being loaded in so i checked task manager and saw that the CPU was sitting again at 0.8 GHZ very Strange. So i quit the game ran Cinebench and the CPU peformed just fine so that got me to thinking. I then installed FurMark and as soon as i hit Run and it Utilized my GPU my CPU Drops to 0.8GHZ and stays there and as soon as FurMark is off and the Dedicated GPU isn't in use Anymore my CPU jumps up to Normal Performance.

Since i already installed Windows twice now i am going to Install SteamOS or Ubuntu and check if there problem is there aswell.

 

[geofelt]

By default, a laptop will use the discrete gpu when plugged in and the integrated when on battery to save run time.
The problem is that when plugged in, the cpu cooler can't cope and you will throttle. That looks like a low clock and hith cpu utilization.

What to do??

First, see that your cooler airways are clear and that the cooler fan is spinning.
Use a windows balanced power profile, not the performance profile.
Set a minimum cpu performance to something like 20%

It is counter-intuitive, but, try changing the windows balanced power profile advanced functions to a max of 90% instead of the default of 100%
You may not notice the reduced cpu performance.

 

[Killermruc]

By default, a laptop will use the discrete gpu when plugged in and the integrated when on battery to save run time.
The problem is that when plugged in, the cpu cooler can't cope and you will throttle. That looks like a low clock and hith cpu utilization.

What to do??

First, see that your cooler airways are clear and that the cooler fan is spinning.
Use a windows balanced power profile, not the performance profile.
Set a minimum cpu performance to something like 20%

It is counter-intuitive, but, try changing the windows balanced power profile advanced functions to a max of 90% instead of the default of 100%
You may not notice the reduced cpu performance.

I did some more test and i think i found the root cause of the issue

I Noticed that whenever a workload is applied to the Dedicated GPU it kills the Entire Power to the CPU. Once Furmark is closed and Dedicated GPU isnt in use Anymore clock go right back Up. That would also match up with the issue prior that whenever i attached the AC adapter it would switch to the Dedicated GPU from iGPU as far as i know and kill all the CPU power.

Ive also Tried some other stuff

Repasted CPU and GPU but before repaste temps were 50 degrees Celsius so didnt make a change

Applied Thermal pads everywhere i could didnt make a change

Ran the Laptop sideways with the bottom cover removed for maximum airflow didnt make a change

I got a new OEM ac adapter didnt make a change

I change out the RAM didnt make a change

I changed the SSD to a different one and installed Linux and the same Problem still exist there

+ The other fixes i tried in my comments posted above

I am now out of ideas on what to do to make it peform

Standalone both parts performed perfectly fine full benchmark scores and everything but as soon as there is any Load on the GPU the entire performance of the CPU just drops