Hello [NAME],   As my colleague mentioned, we cannot confirm if this card is compatible with the R750xa because it is not listed at supported. It can work or not, we cannot confirm.   Also is not listed here if you search by your saver id: Qualified System Catalog ([URL]   Regards.
Is the Nvidia Quadro RTX 4000 compatible with the Dell Poweredge R750xa Server?
Nvidia Quadro RTX 4000 compatibility