CPU power throttling to 0.8GHz on incorrect CPU package power?

[lennson]

For no apparent reason the computer started running slowly from time to time. Using ThrottleStop to monitor it can be seen that while a game is running in the background the CPU repeatedly cycles between running at full speed for several minutes (where power CPU package power usage is reported to be very low) to being power throttled to 0.8GHz (where the power usage is reported to be very high).
[See attached images.]

Any idea what is going on to cause the PKG power to behave so strangely?

The CPU in question is an old intel i5-4200U so could this be attributed to some form of CPU hardware sensor malfunctioning?

 

[FreedomEclipse]

Paging @unclewebb

 

[Caring1]

What GPU is in that laptop?
The i5-4200U is a 15W TDP CPU so I assume it has a discrete GPU also to reach aver 50W package power.
Intensive GPU usage in games can result in the CPU dropping power to compensate to remain in the package power limits.
Hopefully our resident Guru can shed some light.

 

[lennson]

What GPU is in that laptop?
The i5-4200U is a 15W TDP CPU so I assume it has a discrete GPU also to reach aver 50W package power.
Intensive GPU usage in games can result in the CPU dropping power to compensate to remain in the package power limits.
Hopefully our resident Guru can shed some light.

There is no GPU, just the integrated GPU in that CPU chip. And yes going over 50W doesn't make any sense even though the 15W TDP is a pretty serious underestimate the PL1 is 25W and the PL2 is 31W so 50W is still way higher than what should be possible.

Edit: I should also mention that in the case when it is stuck at 0.8GHz and claims that it is using so much power (~48W) the temperature remains low and the fan doesn't spin up. This is in contrast to when it is running at full speed (2.2-2.4GHz) and claims to be using ~7W, the fan spins up.

 

[MentalAcetylide]

This is why I will never ever buy another laptop again for any kind of gaming or workloads that are taxing to the CPU. Too many issues can crop up due to the battery, PSU, and/or the software that "preserves" battery life. Most likely its an issue with your battery, but I could be wrong.
At one point, I had to take my Alienware i7 to a tech and have him disable part of the software because during charging, the battery-charging icon would frequently pop up. I could be gaming full-screen and it would pop up on top of everything. Then there's the issue of the CPU automatically underclocking whenever it feels like it when using "battery preservation setting" with no way to turn it off or have it do the process later. I just don't bother using battery preservation anymore and just keep it charged 100% for weeks at a time.
I haven't tried looking around for one lately, but I really wish they made laptops with an option of not needing a damn battery. I would be more than happy to carry a heavier PS around with the laptop if it means the system doesn't have to run underclocked at a lower wattage.

 

[lennson]

My problem seems to be caused by an incorrect uncore power usage measurement.

It seems to be essentially the same as that problem described in,

35W Uncore on 15W 0.13Ghz 5200u. CPU Problem

Hello guys, I found an old laptop in my house which I stopped using a long time ago bc it became very slow. I though it was bc of its hard drive but I was wrong. When I checked Task Manager the CPU is stuck at 0.13 or 0.48 Ghz depending on the restart. I read a lot of things online but nothing...

www.techpowerup.com

However, I still have no idea how to fix it as the solution there was that the problem magically went away...