I only want to close this thread with an update, in case going forward any more Dell customers want to use a bootable NVMe SSD: So, as I expected, and despite some tenacious opinions to the contrary above, I got it to work now (last weekend). And clearly, the PCIe x16 slot is not "only for video", no. Makes no sense anyway, because the SSD in it was working well as storage drive already from the first minute. Now I have two Win10 installations currently, but I will free up the earlier one on the other SSD. Because my newest Win10 install on the NVMe SSD boots and works great!  I do agree fully with the win-raid forum post though, that "Clover adds a slight delay to the boot process itself". While this was obvious always, the word "slight" is misleading: Booting the SAME Win10 install from my other (SATA) SSD is like the speed of light in comparison. This NVMe boot delay may be reducible further, when I have studied all plist file settings. Either way I feel I can already reliably conclude: For those used to experiencing "2-sec boots" from an SSD will not be impressed by the much-said "speed increase from NVMe SSD". I indeed have been used to those felt-2-sec-boots. And now I wait much much longer. But on the positive: I can again use my other SSD for other things than Windows. Speaking of it: Did you (readers here) know that a Crucial SSD can have superior quality? Mine is already 8ys old, but going strong like new. Yeah, I checked it of course too.  
Hello everyone! I hope you can enjoy things a little, despite covid.I read even more these days, lol. So, I'd been searching here for the last 8 days, and now popped up "Can't find what you're looking for? Sign up and ask for yourself", LOL, I do that I thought. So I've also searched the web up and down, but so far none of the solutions anywhere have helped my Dell... I hope this doesn't disqualify me now in some way, I bought the XE2 i7-4770S with Win10 installed online as a great reseller deal in ... Germany. And to my surprise this meant, now everything is in German unfortunately. I was unaware that these days software and even BIOS(!) gets all translated. I have asked the reseller to change it all to English for me, but I have yet to hear back. Anyway, my unsolved issue is, I downloaded the Dell Service Assist ( , is still in Professional Service for another week), but to my surprise it didn't update the BIOS (Dell Inc. A22, 02.02.2018). Based on online research incl. here, my guess was, the BIOS should first get updated to a modern UEFI, and that would then magically get the NVMe SSD installed in PCIe x16 slot to appear in the boot list and I could boot from it. But not so.  So then I changed the whole Win 10 (German for now) from MBR to GPT to be able to change from BIOS to UEFI, which was an option already thanks to the prior owner having updated the BIOS in 2018. Both was successful. It still wouldn't boot from the NVMe SSD though. So next, I tried "the Clover Bootloader way", which looks like a daunting task and has the clear disadvantage that "Clover keeps all running in Turbo mode all the time", which isn't necessary and really unsuitable in my situation. Regardless, it still doesn't boot the NVMe SSD. Contrary to the views online that say the install device doesn't matter, maybe the reason is that my USB SD-card reader is broken and so I tried all installs from a separate USB SSD that I have. All NTFS formatted, properly on GPT, and "burned" the same way onto it as it's being normally recommended to "burn" (lol) onto a USB stick. Physically/Technically no difference, I agree with those who say so. Either way, the ordered new USB sd-card reader will arrive tomorrow, and then I'll be able to rule out that as well. 1) Interesting is that I did manage to get the NVMe SSD in PCIe x16 slot (with adapter of course) successfully recognized in ... lo and behold... Win10! Both in File Explorer and in System summary. Even while on MBR. 2) Currently the Dell boots Win10 from a slow HD installed by the reseller. My ultimate goal is to have a dual boot with- Ubuntu in partition 1 of the NVMe SSD,- and Win10 in partition 2,- and further partitions for my own stuff, with >30% of the SSD kept free for "garbage collection", or what it's called. 3) I have ISO install files for both Ubuntu and Win10 English on a different SSD, which I can even clone to USB sd-card reader when it arrives tomorrow. >> My thinking however is, will I be able to get the NVMe SSD in PCIe x16 slot get recognised as boot device then, or shouldn't I better get the BIOS/UEFI version Dell Inc. A22, 02.02.2018 updated first today? >> But the Dell Service Assist doesn't offer any updates, it seems. Can anyone point me to the right UEFI version and install page, that will allow to boot from my shiny Samsung Evo 970 Plus, if an update first is necessary?  
Optiplex XE2 i7-4770S Tower: NVMe SSD in PCIe x16 slot not recognised in its 
BIOS version A22, 02.02.2018