Temperature throttling on XPS 7590 using ThrottleStop without any apparent reason

[herr.vorragend]

Hello there!

First i want to say thanks for all the super helpful undervolting advice in this forum!

After i've got myself a new 3080 eGPU recently (for rendering pruposes mostly, but i love to game too) i've been trying my best to make my i7 7950H keep up.
I've been going through the regular undervolting procedure, managing to drop my temps by quite a margin while trying to manage the maximum sustainable turbo.
I noticed today that during long benchmarks i keep running into some thermal throttling even though my CPU cores will barely hit the 95° mark. (The PROCHOT on my device is 100°)
From what i gathered here in this forum it might be a faulty / too hot sensor somewhere not directly related to the CPU?

I've attached my ThrottleStop setup, log and a HWMonitor reading.
My idea here is to make the CPU keep a certain turbo wattage constantly for smoother gameplay.
I manage to go as high as 56 on short and long power limits before my CPU started to sometimes peak around 96°, but generally running at around 94-95°.
Around the 50 watt mark everything runs smooth on 12 threads, 6144M with CPU temps maxing at 90°

Unfortunately i cannot figure out what causes the temperature throttling.
Am i doing something fundamentally wrong here?
I would be really thankful for any advice.
Have a good evening!

 

[unclewebb]

Dell has disabled CPU voltage control in your XPS laptop. The undervolt settings you have entered in ThrottleStop are not doing anything. At the top middle of the FIVR screen it shows FIVR Control - Locked. You will need to find a previous BIOS version or try using the BIOS Reset to Factory option. Advanced users will need to edit the UEFI variable to try to unlock this feature.

The log file does not show CPU thermal throttling but it does show VRTEMP throttling. This means the voltage regulators are getting too hot. More bad design by Dell. There must not be enough airflow over them or they saved some money by not installing a proper heatsink on them. Not sure how to fix that problem.

When PROCHOT 100°C goes red, that confirms thermal throttling somewhere on the CPU package. It was likely one of the cores that got this hot but it could be another sensor anywhere within the CPU package. You could try replacing the thermal paste to help get the temps down.

If you can get CPU voltage unlocked, reducing the volts will make the difference between a useable laptop and an unusable one. As is, the XPS has been under designed.

The only other option to reduce heat is to reduce your CPU speed. The register that locks voltage control also locks the turbo ratio adjusters. To lower the CPU speed, open the TPL window and use a lower value for Speed Shift Max. Somewhere around 30 to 36 should help.

 

[nguyen]

Wait...so you are not even using the dGPU inside the laptop, yet the CPU and VRM are that hot while consuming only 56W ? DELL laptop is a joke it seems.

 

[herr.vorragend]

Hello. Thanks for the reply.

Dell has disabled CPU voltage control in your XPS laptop. The undervolt settings you have entered in ThrottleStop are not doing anything. At the top middle of the FIVR screen it shows FIVR Control - Locked. You will need to find a previous BIOS version or try using the BIOS Reset to Factory option. Advanced users will need to edit the UEFI variable to try to unlock this feature.

Oh well. I've been a bit suspiscious about TS not showing the adapted voltage on the right side of the window, but i could have sworn that it made a temperature difference adjusting it..
I read about features being locked in recent BIOS updates, but i figured its just the turbo ratios nothing else. I dont reaaally wanna go to another BIOS version, since the eGPU support seems to be pretty good on this one. I guess i'll give it a try though.

The log file does not show CPU thermal throttling but it does show VRTEMP throttling. This means the voltage regulators are getting too hot. More bad design by Dell. There must not be enough airflow over them or they saved some money by not installing a proper heatsink on them. Not sure how to fix that problem.

When PROCHOT 100°C goes red, that confirms thermal throttling somewhere on the CPU package. It was likely one of the cores that got this hot but it could be another sensor anywhere within the CPU package. You could try replacing the thermal paste to help get the temps down.

Okay pretty much what i was thinking. the PROCHOT warning I just didn't reset after some tryouts in the beginning.
I've already repasted three times (after my first two tries made a temp difference between cores of up to 8°, so i'm quite happy with that result now).
I also added a hand tailored heat sink on the back of the original one made from several copper sheets to spread the heat a little better. I've already seen temp improvements of about 10°.
What might be the cause is, that while applying this I smushed some of the thermal pads cooling the chips around which might be the cause for the VRMTemp throttling.
I will get some replacements today and try again.
Also i will add extra heat sinks to the uncooled MOSFET and VRM chips.

If you can get CPU voltage unlocked, reducing the volts will make the difference between a useable laptop and an unusable one. As is, the XPS has been under designed.

The only other option to reduce heat is to reduce your CPU speed. The register that locks voltage control also locks the turbo ratio adjusters. To lower the CPU speed, open the TPL window and use a lower value for Speed Shift Max. Somewhere around 30 to 36 should help.

Yeah the laptop seemed to have reaaaally bad cooling from the start.
Going down further with my CPU speed is not and option.
I will go out, get some new cooling pads, repaste, reroll BIOS and start again!
I'll get back to you with some fresh results.

Wait...so you are not even using the dGPU inside the laptop, yet the CPU and VRM are that hot while consuming only 56W ? DELL laptop is a joke it seems.

Uhmm. Yes. To be honest it's something i'm aware of since i got the machine a year ago. It get's crazy hot.
But to be fair the Dell service hase been top notch so far. Had a bad display on the first XPS i got, got it replaced on sight within 48h, drowned it at work, got a new upgraded replacement.
So i guess there's ups and downs here.


So but my underlying idea about keeping long power max and short power max to the same wattage for less fps drops/jumps makes sense?

Thanks so far guys.
I'm off getting some parts and i'll get back with some fresh results.

Okay soooo.

I changed all thermal pads on the laptop, repasted again, added heatsinks to four uncooled chips and reset my BIOS.
Managed to undervolt properly now (with the settings shown above) and for now i'm running 56W in turbo stable at 93-94°, without any throttling and VRTemp issues.
For now i'd call that a success.
Any ideas how i could improve temperatures any further? I haven't tried undervolting any further yet. For today i'm happy it's all stable.
You think though undervolting the agent and unislice will gain me anything?
Also

So but my underlying idea about keeping long power max and short power max to the same wattage for less fps drops/jumps makes sense?

By the way, this is how my XPS looks on the inside now. It ain't pretty but it's workin.
I might try out extra cooling pads on top of the main heat sink instead of my self made copper solution.