CPU started constantly throttling today...

[ludibert]

Good Evening,

I have an HP Pavilion 15 Laptop with an i7-8750H inside of it and I mainly use it for producing music, watching videos and rarely gaming.
As of today, I noticed Windows started lagging, so I checked if Task Manager had some answers... The processor's clock speed was stuck at 0.79GHz and so a quick search got me to select a different power plan, which got rid of the 0.79GHz limit. But now virtually every time I do something on the laptop the clock speed is around 0.79-1.4GHz and when I don't do anything at all it goes up to 2.8-3.2GHz. The result is a terrible amount of lag and overloads in my music software and an overall slow-down.
I installed ThrottleStop and it almost constantly shows POWER errors. I'm not an expert and don't really know what I am doing at this point but I have tried lowering my power throttling limits - without success in fixing the problem. Temperatures are very cool so it cannot be a thermal issue.
Any kind of help is greatly appreciated!

Thank you

 

[unclewebb]

You can try checking the Short Power PL2 check box in the TPL window but I do not think that will make any difference.

Did you install a BIOS update recently or perhaps a Windows update?

The low ball turbo power limits are being sent to the CPU via an embedded controller EC. When the EC power limits are lower than the MSR and MMIO power limits, the EC power limits can force the CPU to slow down to as low as its minimum speed.

Temperatures are very cool so it cannot be a thermal issue.

It is possible that a sensor somewhere on the motherboard has failed. A sensor can feed monitoring data to the EC and then the EC can decide if a computer should throttle or not. If this monitoring data is not correct, the EC can decide to throttle the CPU when there is no legit reason to be throttling. That is what the log file shows.

I do not know how to fix this problem and I cannot remember anyone fixing an EC throttling problem. You can start replacing parts like the battery and the power adapter. This might not make any difference if the sensor is somewhere else like on the motherboard. It is difficult to find any publicly available documentation that explains what sensors are used in each laptop model.