Dell G5 5587

undervolt is successfully working on the latest BIOS revision (1.21.0)

I used this method to unlock undervolting, which required Windows. Instructions are pretty good, though one little nitpick, the file on the USB should be named /EFI/boot/bootx64.efi

Then once unlocked, you can setup undervolt as per the instructions on the main page. Note that on later versions of Ubuntu, you will need to install python/pipx in a virtual environment.

I have cpu and cache set at -125mV and intel gpu set to -75mV.

Temperatures for light work (browsing etc) decreased 4C. You can also decrease temperatures further by choosing different Prime profiles for nvidia/intel. Eg sudo prime-select intel which turns off the nvidia card and runs off Intel only decreased temperatures about 7C. And turning off Turbo Boost can also decrease temperatures further. You can do that in the BIOS, or with undervolt.

My idling/light work temperatures are now about 43C on Ubuntu 23.04. I have Turbo enabled, nvidia-settings to the On-Demand Prime Profile (I run On-Demand because I HDMI out to my monitor), and the Balanced Ubuntu Settings Power mode.