Lots of people on the Notebook Review forum are using Intel XTU or ThrottleStop to undervolt their 8750H CPUs. Use a negative offset votlage. Somewhere around -125 mV for the CPU core and CPU cache is a good place to start.
ThrottleStop has a few more features that can help you get the most out of an 8750H. It also applies the voltages more reliably after you resume from sleep or hibernate mode. It is best to use Intel XTU or ThrottleStop but not both at the same time. Both programs are writing to the same voltage control registers in the CPU. Intel XTU gets a little confused when another program is changing things behind its back.
Some liquid metal is a great idea. The 8750H makes for a powerful laptop when cooled and properly setup.
It's the Dell G7 7577. XTU is currently running with -.125 on the CPU. I took a look at throttlestop and it looks powerful but I am short on time to learn how it all functions.
Still reaching close to 100C under gaming load even with the lappy cooler keeping the intake supplied with nice fresh air. Ambient temp is ~22C.
It's a really great CPU but boy does it run hot!
Yeah it runs a bit hot, I have a dell G7 as well but with a 1050ti.
I'm running -145mv on cpu core and -125 cache, intel's XTU doesn't allow you to undervolt with different values as far as I know, so I'm using throttlestop.
Another good thing to try is to undervolt yout graphics card since the cooling solution is tied to the cpu as well, there are some tutorials online on how to do that with pascal GPUs.
Even with all that the laptop doesn't run *cool* but it does help with thermal throttling.
Edit: Cache undervolt can cause freezes and BSOD more often than cpu, reason why I switched to throttlestop.
The 8750H is indeed hot, I've used grizzly conductonaut and even on idle after a reformat it still manages to generate a lot of heat that I kind of gave up trying to find new solutions other than the -125mv reduction and a slight elevation for the vents.
As for throttlestop I use the guide from this video and its pretty easy to follow,
Apparently some cooling solutions were not made for i7-8750H but rather for i7-7700HQ.
Since 7700HQ runs at 3.4GHz some say it's better to underclock 8750H.
I run my [email protected], -200mV core, -62.5mV cache.
Idle temps are around 45-50°C, while gaming it's usualy 60-70°C, but can reach 80°C.
Maquibut, you need to be careful running that large of an undervolt on your core. You can end up decreasing performance beyond -0.150mv as the cpu will spend less time boosting to the requested speeds.