Hello,
I have tried the latest Intel graphics drivers 27.20.100.8935, and installed a newer Intel Dynamic Platform
and Thermal Framework Version 8.7.10400.15556 WHQL found on the web. Neither made any difference to the throttling.
I have completed a fresh install of Windows 20H2, this has made no change to the throttling, though after a restart performance does return to normal.
The problem seems to occur when the Surface is used, then shutdown. Once the Surface is switched on and battery is below 35%, throttling occurs until a restart. Usually on restart will resolve the issues.
You can disable DPTF, but this defeats the point of having the CPU and GPU power and thermals managed.
There does seem to be some relation between DPTF and battery level effecting performance. An un-related test shows different performance depending on battery level with a Linux test on a Core i7 1165G7. (Tiger
Lake + Renoir On Ubuntu Linux For Battery vs. AC Performance - Phoronix)
Hopefully as performance can be returned with a restart, its something that can be fixed with firmware/software, though is has been a year!
MuckRogers