I think, we have a problem here, that needs to be solved on multiple
issues.

* there's throttling hitting in to avoid a dGPU reach its fall-off limit
which is 76° (T580, i7-8550u, MX150). The only possible way to stay
below this thermal limit is to power down the CPU massively, which leads
to =>

* the dGPU isn't throttling down itself enough. In tests (glxsphere) my 
findings are:
dGPU runs at about 1600-1700Mhz, not going down further. I guess this is a 
result of the gpu itself has a thermal limit of around 95° and gpu's own 
throttling will kick in much later than 76°, making the gpu not helping in 
cooling down with slowing down more.
I wasn't able to get a reading of the power consumed by gpu, nvidia-smi does 
not offer these (nvidia-396). Thus leading to =>

* There's an imbalance between gpu's and cpu's abilities to thermal
adapt. As gpu isn't able to, cpu is and does which leads to =>

a) a system running on brakes to manage heat, for to stay below a poosible gpu 
fall-off (full gpu power and frequency stable along time with cpu going down to 
only 3-5W 
or 
b) a system running at the possible performance with using the cpu's full 
potential, but only being able to use ⅓ of dGPU's capacities 

Conclusion from my perspective:
There's a need to balance :-)

* there's a need to have influence on gpu's abilities to throttle earlier (=> 
nvidia)
* Lenovo-fix being enhanced to provide some kind of profiles, which are 
dynamically providing usecase profiles (easiest way to test is: set temp in 
Lenovo-fix to max 75°. As both, cpu & dGPU producing heat and 76° is fall-off, 
staying below that keeps system from throttling.)

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https://bugs.launchpad.net/bugs/1763144

Title:
  Significantly lower power and thermal limits on ThinkPad T480s (and
  probably others) than on Windows

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