To give some numbers to the comment I made previously in this thread, with an XPS 7390 2-in-1:
Single core turbo 3.9GHz, maintains indefinitely, temperature hovers around ~75 degrees, fans around 5000RPM
All core turbo: Keeps 3.4GHz and ~45W TDP for around 10 seconds, before dropping to 2.7GHz and ~25W TDP indefinitely. Temps still around ~75, with the fans around 8000 RPM.
That's without any undervolting, but with the processor set for 25W TDP (like the Windows "Ultra Performance" mode). Adding in some undervolting gets the all core turbo up to 2.9GHz.
Can you tell me what you did to set it to 25watt? I swear I've tried this a few times going through Throttlestop tutorials with different usb-c chargers (from the stock 67w up to 97w) and either that option was greyed out or I never got it to actually do 25w.
Single core turbo 3.9GHz, maintains indefinitely, temperature hovers around ~75 degrees, fans around 5000RPM
All core turbo: Keeps 3.4GHz and ~45W TDP for around 10 seconds, before dropping to 2.7GHz and ~25W TDP indefinitely. Temps still around ~75, with the fans around 8000 RPM.
That's without any undervolting, but with the processor set for 25W TDP (like the Windows "Ultra Performance" mode). Adding in some undervolting gets the all core turbo up to 2.9GHz.