These are your boost power limits and if you followed that youtube video and placed PL1, PL2 and IccMAX to unlimited this is why the CPU will run hotter when under load.
The default boost design places a power limit on the CPU so that the cores cannot all run at the maximum boost frequency at the same time. For example, by default when all your P-cores are fully loaded they do not run at 5.6GHz, they will generally be around 4GHz (maybe more / less). This is because of the limits in place / design spec, The CPU is only allowed to consume up to 157W Intel spec in boost mode.
If you change the PL1, PL2 and IccMAX to unlimited it means the CPU will try to use as much power as it can during boost mode, in Cinebench your CPU would likely have been running all cores higher than 4GHz, that means it would have been using a lot more power and consequently generating a lot more heat despite undervolting.
Also something to think about when undervolting. Your CPU is always trying to boost itself no matter what, if you make it run cooler it has the potential to boost higher, to the point that undervolting may have minimal impact.
In this test, -0.8 sees 4.3GHz vs 3.7GHz average across the P-Cores with minimal impact to load temperatures. The only improvement is the benchmark score as it was able to boost higher.
https://www.youtube.com/watch?v=w24rSJpUS6s
https://www.youtube.com/watch?v=fRRN0MUmUnk
For example, CPU boosts to 3.7GHz runs 100 DegC.
We undervolt it so now at 3.7GHz it runs cooler.
CPU knows this so will increase the boost until it hits 100 Deg C again.
So undervolting has helped it run cooler but the boost mode took advantage instead, so in practice it doesn't translate to that much lower temperatures when it is under a very high load.
And not matter what you do, if a single core boosts to 5.6GHz it will always show a higher temperature in games.
But before adjusting settings you need to determine how hot / how efficient your cooler is performing when the CPU is running base frequencies as if there is an issue it will be hot no matter what you do.
I have more testing and explanation here (give hardware monitor a go and try running some games too, like I show)
https://www.electrostingz.com/2025/06/how-to-check-laptop-cooler-performance-intel/
If your base frequency temperature is terrible, fix that first then start adjusting settings, I would expect your CPU to be about the same as my 14900HX at base frequencies. This will also show you how hot your laptop will run as a minimum too. (Under 75 Deg C is good in a non boost state.)
