Question unreal power limit throttling on dell g7 with an i7-8750h

May 15, 2022
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i have a dell g7 7588 that i purchased back in 7588 and it ran fine for the most part until late 2019, after which it would constantly thermal and power limit throttle. I cleaned the internals and repasted the cpu and then it ran fine for another 6 months after which i had to do the same again as the i7- 8750h would drop down to 0.798 clock speeds and stay there for a solid couple minutes. I kept on repeating the process everytime i faced this problem until last week.

i have repasted and undervolted the cpu and the temps usually range from 47 on idle to 71 when im playing valorant and even then power limit throttling occurs and the cpu speeds suffer and as a result my fps drops to 15 from 160-170. I feel like i have tried and tested every fix or tweak out there but nothing helps and this "gaming" laptop has been reduced to an internet machine.

has anyone else here faced power throttling at such low temps? if so, were u able to fix it?
 

uWebb429

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May 22, 2020
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has anyone else here faced power throttling at such low temps
Definitely yes. You are not alone.

This is a common problem with many, many Dell laptops. Dell decided to dream up a new power limit throttling scheme when Intel's 8th Generation CPUs were introduced. This great idea was not that great when these laptops were brand new. Things only got worse as these laptops got older.

What seems to happen is there is an embedded controller (EC) that can send turbo power limits directly to the CPU. These power limits are separate from the MSR and MMIO turbo power limits that ThrottleStop lets you control. The EC seems to be sending a 5 Watt or maybe even a 0 Watt turbo power limit to the CPU. This forces the CPU to run as slow as possible as it tries to get power consumption down to this ridiculously low level. The result is a CPU that randomly gets stuck at 798 MHz for extended periods of time. This of course makes the laptop completely unusable when trying to play any game.

Turn on the ThrottleStop Log File option and you will have a complete record of exactly what is going on. It will confirm this problem. You can copy and paste the data to www.pastebin.com if you want me to have a look.

were u able to fix it?
Now the bad news. There is no fix for this design problem. You can try contacting Dell but as far as I know, Dell is still not willing to admit that this is indeed a serious problem. The cost to properly fix all of the Dell laptops that have this problem would be massive. Your laptop is just the tip of the iceberg.

The only thing that might help make your defective laptop useable is to lower the CPU speed significantly. The severe throttling seems to be triggered by the average CPU temperature. When the average temperature gets up somewhere around 90°C is when these laptops go into severe power limit throttling mode. You can use ThrottleStop to lower the Speed Shift Max value in the TPL window to try and control the CPU speed and heat output. Post some ThrottleStop screenshots and a log file if you need help.
 
Reactions: xansarcade

uWebb429

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May 22, 2020
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@xansarcade
Can you show me a ThrottleStop Log File from a gaming session? Hopefully at least 15 minutes. You can copy and paste the log file data to www.pastebin.com

Does the TS Bench report any errors? An undervolt of -154.3 mV is on the edge of stability for most 8750H. The core and the cache offset do not need to be set to the same value. Some users get better overall results by reducing the amount of cache offset voltage a little and then increasing the core offset voltage to -175 mV or -200 mV. This seems to trick the CPU into using less voltage when running code with a lot of AVX instructions.

Here are some examples that a user sent me. The download includes 3 pictures of some Cinebench testing on an 8750H.
https://drive.google.com/file/d/1B2HZjwlS6B5vO-m6HrkYMuiu8yVh3LvY/view?usp=sharing

Use Cinebench R20 or R23 when testing different voltages. I prefer R20 because it defaults to a single test.

 
May 15, 2022
6
0
10
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@xansarcade
Can you show me a ThrottleStop Log File from a gaming session? Hopefully at least 15 minutes. You can copy and paste the log file data to www.pastebin.com

Does the TS Bench report any errors? An undervolt of -154.3 mV is on the edge of stability for most 8750H. The core and the cache offset do not need to be set to the same value. Some users get better overall results by reducing the amount of cache offset voltage a little and then increasing the core offset voltage to -175 mV or -200 mV. This seems to trick the CPU into using less voltage when running code with a lot of AVX instructions.

Here are some examples that a user sent me. The download includes 3 pictures of some Cinebench testing on an 8750H.
https://drive.google.com/file/d/1B2HZjwlS6B5vO-m6HrkYMuiu8yVh3LvY/view?usp=sharing

Use Cinebench R20 or R23 when testing different voltages. I prefer R20 because it defaults to a single test.

i did the changes right now and here's the logfile with them while playing valorant https://pastebin.com/CgnhHCXM

ts bench starts to report errors around the -170 mark, i went through the log file and temperature is rising to 95 degrees in it. It hasn't even been 2 weeks since i repasted with arctic mx-4, should i use a different thermal compound like the ge lid gc extreme? or is it going to be the same result again. Also this could be a really stupid question but my laptop's battery only lasts for around 30 mins on a full charge so i have unplugged it and i use it on AC power, even though the same things happened when the battery was connected would this ever influence power throttling?
 
May 15, 2022
6
0
10
0
i did the changes right now and here's the logfile with them while playing valorant https://pastebin.com/CgnhHCXM

ts bench starts to report errors around the -170 mark, i went through the log file and temperature is rising to 95 degrees in it. It hasn't even been 2 weeks since i repasted with arctic mx-4, should i use a different thermal compound like the ge lid gc extreme? or is it going to be the same result again. Also this could be a really stupid question but my laptop's battery only lasts for around 30 mins on a full charge so i have unplugged it and i use it on AC power, even though the same things happened when the battery was connected would this ever influence power throttling?
oh and i'll run the cinebench as soon as im done with work. i really appreciate your help here!
 
May 15, 2022
6
0
10
0
@xansarcade
Can you show me a ThrottleStop Log File from a gaming session? Hopefully at least 15 minutes. You can copy and paste the log file data to www.pastebin.com

Does the TS Bench report any errors? An undervolt of -154.3 mV is on the edge of stability for most 8750H. The core and the cache offset do not need to be set to the same value. Some users get better overall results by reducing the amount of cache offset voltage a little and then increasing the core offset voltage to -175 mV or -200 mV. This seems to trick the CPU into using less voltage when running code with a lot of AVX instructions.

Here are some examples that a user sent me. The download includes 3 pictures of some Cinebench testing on an 8750H.
https://drive.google.com/file/d/1B2HZjwlS6B5vO-m6HrkYMuiu8yVh3LvY/view?usp=sharing

Use Cinebench R20 or R23 when testing different voltages. I prefer R20 because it defaults to a single test.

did a couple runs of r20 and my cpu does not hit anywhere near 3.9 at any point in the test. It usually starts off at 3.4 and throttles down to 2.9 and temps hover between 89-98. For the test i changed the turbo ratio limits to defaults in the hopes that the clocks would go up , but that didnt happen. i am going to get it repasted with gc extreme tomorrow to see if that helps the case. i had used arctic mx4 last week and it only ran fine for like a week after which it started to throttle again.
 

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