This forum post may help. As per Dell support the specs call for 4 TB HDD as maximum. You can install more than 1 x 4 TB HDD but it appears to be a limitation of the MB.
I have a Dell XPS 8930 on Windows 10, fully updated. I just bought a new, 16TB X16 internal hard drive to use for basic storage. It spins up just fine, but the computer doesn't list it as a drive. The computer acts like it doesn't even know an additional drive is connected. I've used 2 different data cables, but no luck. Naturally I looked online for solutions. I see that the BIOS on the comp may have to be reconfigured in order for the computer to look for and recognize the drive, but I've had no luck doing this. When I go into settings - recovery and do a restart to adjust BIOS settings, the comp powers on but the screen stays black and nothing boots up. I've also seen a suggestion that there may be a size limitation on additional hard drives. At 16TB I wonder if maybe that's my issue. But one way or another, I'd like to be able to use this new 16TB HDD. Any help would be appreciated!
XPS 8930, won't recognize secondary hard drive