Hi,
It is interesting to notice that an Intel server that can be used both as Workstation and Server doesn't have a linux driver for the onboard GPU and that no other Nvidia video GPU is "validated" to be used.
For any other user that be interested, the Nvidia GTX 970 works for sure if mounted on slot1 connected to CPU1 and in the Bios the on board GPU is disabled.
Many thanks
Daniele