As mentioned above, typically this option is called "SATA Operation", and despite the name it also affects NVMe SSDs. If you can't find that, then Dell may have changed the name of that option in newer systems. I haven't used an Inspiron 7490 specifically.
This has worked for many people over the years. Please be sure to create a Full disk Image before attempting.
The correct way to switch from RAID to AHCI is to make the BIOS changes then, USe Disk Part to Clean your Disk/SSD and then Do a Clean install to the AHCI disk/SSD
It is important to use Diskpart to Clean your Disk/SSD prior to completing the Clean Instll, The easist way is to start the clean install once you get to the part where you need to select a volume to install too. Press Shift and F10 this will bring up a comand prompt type in
Select the disk you want to Clean," it should be the only disk you have connected"
after clean is complete your Disk/SSD will be in RAW condition exactly as it first came from the factory
Your Disk/SSD should now be available as a volume to install too.
Thanks for your details.
Currently, i'm blocking at the step : Reboot into UEFI/BIOS and change to AHCI.
I can't find any item in 7490 bios to 'change to AHCI'. Dell removed this option from 7490 BIOS. I believe they will add it back in coming bios release.
I have not heard if they will. We will have to wait until the next bios release.
I saw the new BIOS 1.1.1, and upated my 7490. But unfortunately, The 'switch to AHCI' feature still hasn't added in. Is there anything blocking to add it?
@DELL-Cares I'm sorry, but this isn't just a case of offering limited Linux support. Limited support would imply that customers who wanted to run Linux might still be able to figure out their own workarounds or accept certain limitations. But not offering AHCI mode makes it completely impossible to run Linux. In addition, not offering support for AHCI mode creates problems even for some Windows scenarios. For example, a Windows user with a Samsung SSD might want to use the Samsung NVMe driver instead of Microsoft's built-in NVMe driver, but that requires the system to be in AHCI mode. When the system is in RAID mode, the only driver that can (and must) be used is Intel's RST driver. It makes no sense to me why Dell would force RAID mode to be enabled on these systems without an option to use AHCI mode that disables the Intel RST controller.
This circumstance is very annoying because i bought this laptop so I can install linux since I had a mac before. It is so unusual that you cant install linux on a laptop which costs over 1000 euro and in my opinion there is no reason why I shouldnt be able to install linux so what should I do know?
Well, the only thing I can see is that the advertised OS is only Windows 10, this is a business-class notebook intended for business use. So there would be no reason to support Ubuntu as it is not used for business purposes.
They do not specify that AHCI is not available either.
The reasonIRST is used I assume it that is compatible with all drives and Windows systems If you choose Apple products you use what Apple allows you know this since you moved from Apple products.
I also would assume if Dell were to get enough people complaining that AHCI is not available, they would then rewrite the UEFI/BIOS