So, stopwatch at hands, it takes a grand total of 39 seconds from turning on my Dell XPS 9550 to the user selection screen.
Is it normal? Is it too slow? I am running 18.04.1 with the latest Dell bios (1.8.0). Fast boot in bios settings is on Auto (turning it on did not produced any change) and Ubuntu is booting in Legacy mode from the SSD. I have disabled all other possible booting sources (diskette drive etc.)
Ok, I found out that two big culprits of the slow boot, at least on my Dell XPS 9550, were the LVM and encryption that I turned on during install.
It seems that with some SSD models, this causes a bug that adds up time at boot. I reinstalled without checking those those boxes and boot times are as follows:
Startup finished in 17.153s (firmware) + 7.527s (loader) + 5.377s (kernel) + 919ms (userspace) = 30.977s
Just tried dual booting with my Dell XPS 15 9560. Windows 10 boots in seconds, but Ubuntu could take up to a minute to get to the login screen, and then an additional 30 second to load my user desktop. Unbearable! So I looked into this, and now my boot time is under 10 seconds. Much better :)
So, what did I do? Well, I already had a clean install of Ubuntu (I run 19.10 but should probably work just as fine on 18.04). But first, I updated the firmware, easily done with the Ubuntu Software application, but I also heard this command should do the trick. I don't think this is what actually resolved the issue, but it's recommended to do, nonetheless.
sudo fwupdwgr update
sudo reboot
So what I believe really did it, was installing Nvidia's proprietary drivers. Because I also had an issue where the desktop would freeze very rarely, but for several seconds. So this thread helped me with that, and suddenly the boot time was down. So to install that, just run,
sudo ubuntu-drivers autoinstall
sudo reboot
And all of the sudden, everything is smooth as butter, and boots fast, logins fast. Everything so fast and snappy! Good luck!
