I would like to know the differences between Debian and Ubuntu besides the well known stability and package management or non-free policy. I'll try to proceed with order trying to not forget anything because I'd like to have in this page all the information needed to pick one or the other with awareness before installing (on a laptop mostly).
I'll start saying I'm a Debian 9 (stable) user who has decided to switch to Ubuntu 18.04.1 trying to get better support for NVIDIA Optimus (laptop dGPU-iGPU technology) so I used Ubuntu for just a few days therefore I'm going to start with questions related to my short experience and my needs but I'm open for more answers than I'm asking. For my experience I tried switching to Ubuntu just because of its hybrid GPU support, no other reasons.
1 - Battery life
The first thing I noticed is the battery life: my laptop's battery, with Debian, with airplane mode could last up to five to six hours but with Ubuntu, with same usage, can't go beyond three hours. Why is that? Is there any way to understand what's going on with the battery?
PS. Both distros were using GNOME 3 as dm and the laptop was configured to use the Intel integrated graphic card (dedicated-one wasn't just unused but turned off with
bbswitch in both cases). I'm saying this to prevent answers like "you have to turn off completely the dGPU".
2 - NVIDIA Optimus support
Ubuntu is well known for its user-friendly interface and because it's almost totally pre-configured. However I spent an entire day writing a script to get proper GPU-switch technology working without tearing while playing videos.
On Debian I was using bumblebee but I get lost for months into a well known problem waking up dGPU after suspend (
ACPI problem with dGPU named 3D controller in
lspci output). On Ubuntu I tried
nvidia-prime package with
bbswitch. Mainly I would prefer nvidia-prime because it supports vdpau and get better performance in general using dGPU.
The question is: is there an alternative for Debian with vdpau support?
3 - MAC (
I'm very happy to see that Ubuntu has it by default. Why doesn't Debian have it installed by default?
4 - Secure Boot
Why does Ubuntu have signed kernels but Debian doesn't?
I don't want opinion but reasons. Each distro has its strengths and its faults: Debian is about stability; Ubuntu is about supports.