Back story:
May of last year using the very helpful instructions on this site I modded the UEFI for my Asus Sabertooth x79 to add NVME boot support using a "BIOS" (EEPROM?) chip pulled from another motherboard (same model).

Windows 10 installed without issue on the HP EX920 NVME SSD I got and put on a NVME to PCIe card and life was good, or so I thought.

Over the course of the year I've had this weird crash issue that happens intermittently where the screen goes black.

If I was watching a YouTube the audio will continue to play as normal or if I was in a conference call the audio would continue work for a period of time but I could not connect to the machine via RDP to try to see what was going on.

The things that changed that I thought were suspect was Windows 10, Nvidia DCH driver, NVME drive/modded UEFI. Could I have modded the UEFI incorrectly?

Anyways, to troubleshoot the issue I cloned my NVME drive back onto a SATA SSD using DD from a Linux live CD and put the unmodded EEPROM back in.
To my surprise when I booted my computer up it booted from the NVME drive instead of the SATA SSD!

I'm thinking that was possible because the drive was cloned and the disk signatures are the same.

Also, the SATA SSD shows up as offline in Windows because the signatures are the same preventing it from being used.


Thread topic:
I would like to keep using the NVME drive but random system crashes are annoying so I'm wondering if this "chain loading" (BIOS/UEFI loads Windows Boot Loader from SATA SSD which loads Windows from NVME drive) can be leveraged.

I still don't know if the crashing issue has gone away. It's only been a day so this may be a fruitless endeavor.