When changing the SATA drive setting from RAID to AHCI, and disabling the "Secure boot" option in the BIOS (both actions are needed to install Ubuntu), the booting process gets stuck in the Dell logo for a long time, around 5 minutes, before it makes any progress. Even trying to enter the BIOS again to change those settings makes me have to wait that long.
Also, when booting when those settings on and entering the BIOS, the whole user interface of the BIOS menu, even just moving the mouse cursor around, is extremely slow. Clicking on a menu option on the BIOS makes the screen refresh to the next screen with a very slow transition of about 3 seconds.
I'm have upgraded to the latest BIOS firmware as of April 8, 2017 (Version 01.00.10, 3/9/2017). This bug is currently preventing me from setting up a dual-boot mode with Windows 10 + Ubuntu, which makes the system not usable for my specific use cases. I'd really appreciate if these issues could be resolved soon.
Thank you all in advance.
disabling the "Secure boot" option in the BIOS (both actions are needed to install Ubuntu)
Not if you use a newer version of Ubuntu. If you need to disable Secure Boot you might be causing problems for later. The SATA controller does have to be set to AHCI so Ubuntu will see the PCIe controller on the drive.
Since the system comes with the PCIe drive set to use a SATA controller, if you change it to AHCI you need to go through the process of using msconfig.exe and Safe Mode to change it. If you don't, the controller may not have been switched correctly.
Not disabling secure boot introduces countless issues with the installation of Ubuntu 16.04, for which one has to waste incredible amounts of time looking around for different hacks to solve them. Currently, I'm still stuck in a crash of the Ubuntu installer, which doesn't seem to be able to configure the Grub loader in the EFI partition.
One way or another, the BIOS bug I'm referring to here is present - not when we just switch to AHCI, but when we disable secure boot in the BIOS. And it's not that only the boot process and the BIOS interface are slow, but if you have the patience to go past those points, booting from the USB installer continues to experience a slowdown of 10x-100x. It's as if the machine just decided to work at a small fraction of its speed.
I feel this is a problem that Dell needs to deal with urgently. What is the point in giving the option to disable secure boot if the system is unusable with this configuration?
I agree. The XPS13 could not install dual system. This is very urgent for Dell to solve now. I bought a Dell XPS13 9365 recently. But, I could not use it since I need to install ubuntu16.