i5-8250U always throttle after 5-10 seconds, Throttlestop EDP OTHER and PL1

[DinoMC]

Hi there,

I'm trying to make Turbo Boost usable on my laptop, it pretty much doesn't work at all right now.

Right now, anytime the CPU is used, it stays at 3.3ghz for about 5-10 seconds then drops and starts going up and down wildly between 1.5ghz and 2.8ghz. Weirdly the throttle always start exactly at the same time as the fan going from "silent" mode to full spinning, not sure if this mean anything.
It's usually at 80°C when it starts throttling, but I have seen it stay at 3.3ghz for a few seconds after hitting 80°C so I don't think it's a temperature limit.
This is all while plugged to power, I don't care about Turbo Boost on battery.

While looking this issue up, I heard about Throttlestop and gave it a try.
Everytime the throttle starts, Limit Reasons has EDP Other (Ring) and PL1 (Core & GPU) turning red. Usually PL2 turns red a few seconds before that (Core & GPU) but that doesn't trigger throttling, then it goes back to yellow.
I tried undervolting and modifying Power Limits based on a few threads I found about the 8250U. Anything I change doesn't seem to have any effect on the time before throttle (5-10s). For now, I have reset everything to default. I'm adding the current settings and bench results as attachments.

Do you have any idea what the issue could be, and if there's anything I can try to fix it?

Thanks

PS. Laptop is HP Pavilion 15-bc403nf (HP15BC403NF)

 

[unclewebb]

Some laptops use a turbo power limit that is hard locked to 15W. There is no easy way to get beyond this.

In the FIVR window select the Disable and Lock Turbo Power Limits option. In the TPL window, set the long term turbo power limit to 25W. If ThrottleStop still shows PL1 lighting up in red and your CPU is only drawing 15W, that means your CPU is being forced to 15W and there is nothing you can do about it. HP tends to lock their Pavilion line down.

 

[DinoMC]

If ThrottleStop still shows PL1 lighting up in red and your CPU is only drawing 15W, that means your CPU is being forced to 15W and there is nothing you can do about it.

It does go above 15W for a few seconds but then drop down to 15W and stay there. Does this mean the long limit is hard locked, as you said?
Thanks

 

[unclewebb]

Does this mean the long limit is hard locked

Yes.

Your laptop is locked by HP and is being forced to a maximum of 15W long term.

Lenovo left their C930 unlocked. Same 15W TDP.
Big difference in full load speed when 8th Gen U CPUs are not being power limit throttled.

http://imgur.com/eo0J744

 

[DinoMC]

Your laptop is locked by HP and is being forced to a maximum of 15W long term.

I need sustained high cpu clock speeds so I'm going to return it and try to get a laptop without such a low limit.
Is there some master list of all laptops with low power limit? Or a list of brands to avoid (apparently HP Pavilion is one)?

 

[unclewebb]

It is all hit and miss. A laptop with unlocked power limits today might get an update tomorrow that locks it down. Find a laptop with a 45W H series processor. You will have a better chance of full load performance without severe throttling. Do lots of testing when you get it and be prepared to return it if it does not meet expectations.