CPU Underclocking/Undervolting

[Hawke64]

I am looking for a safe way (software suggestions and step-by-step guides) to decrease the CPU temperature while being able to use the notebook for gaming (Elden Ring, Baldur's Gate 3) and ML (e.g. XGBoost).

Asus ROG GL704G, Intel® Core™ i7-8750H. The CPU reaches 90+C under stress. The goal is <80C without blue screen, ~45C when idle.
The notebook has not been used much and changing the thermal paste at the moment is not an option. I have not found the CPU-related settings in UEFI/BIOS. I have tried to decrease the performance via Control Panel/Power Options, but it did not change anything, and to undervolt the CPU with ThrottleStop by -125mV (cores and caches)*, but it led to hard crash and 3 blue screens. The monitoring software is HWMonitor. Could try with smaller steps (-50mV), though would prefer to know more about the process first.

*the guide used: https://www.digitaltrends.com/computing/how-to-undervolt-cpu-guide/

Edit. Found an official Intel software (https://www.intel.com/content/www/us/en/download/17881/intel-extreme-tuning-utility-intel-xtu.html), which lists CoffeeLake as supported, but not the exact CPU model. If anyone has experience working with, the information would be most welcome.

Edited July 4, 2023 by Hawke64

[Sarex]

You will probably need to find an unlocked bios. There are modding communities that upload bios images that have all the hidden settings unlocked.

[Hawke64]

Thank you for the suggestion. I will look into it, though installing BIOS images correctly might require slightly more experience than I have.

Edit. It seems Asus actually locked the voltage settings in one of the updates (I doubt that the files for a different model would work for mine): https://www.reddit.com/r/ASUS/comments/qdvyui/asus_undervolt_unlocked_for_model_gl704gw_via/

Edited July 4, 2023 by Hawke64

[Sarex]

Updating the bios is simple enough, although it does pose a certain risk of bricking your laptop, so be warned. Never happened to me, but better to be aware of the risks.

As for the bios itself, you can always register and try asking for someone to provide you with the unlocked version. It's a simple enough thing for people who know how to do it.