Linux on Alienware 15 R4

Change SATA controller to AHCI instead of RAID: https://github.com/awesomebytes/alienware15r3_ubuntu14

Get Windows to boot on AHCI mode (SATA options)

For Ubuntu to see the NVME disk it needs to boot on AHCI not on RAID mode (the default). As you don't want to go to the BIOS to change the SATA mode every time you want to boot in one or another OS, we need to force Windows to be able to boot in AHCI mode.

For that follow the instructions (kindly taken from here):

• Run Command Prompt as Admin.
• Invoke a Safe Mode boot with the command: bcdedit /set {current} safeboot minimal.
• Restart the PC and enter your BIOS during bootup (F2 key).
• In tab Advanced change option SATA Operation from RAID on to AHCI mode then go to Exit tab and use Save Changes and Reset.
• Windows 10 will launch in Safe Mode.
• Right click the Window icon and select to run the Command Prompt in Admin mode from among the various options.
• Cancel Safe Mode booting with the command: bcdedit /deletevalue {current} safeboot.
• Restart your PC once more and this time it will boot up normally but with AHCI mode activated.
• Enjoy your awesomeness.

Disable Secure boot

You need to disable secure boot in order to boot any other OS.

Enter your BIOS (F2 key on boot). Go to Boot tab and change Secure Boot option to Disabled.

Note that Boot List Option should be UEFI (it's the default).