Quadro P2200 is not a supported GPU on R720. Not supported does not mean it will not work. We can not guarantee that it will work as it is not validated on the server. Below GPU are supported on R720

CN3GX - Graphics Card, NVIDIA Quadro K4000, 3 GB, 1 DVI-I, 2 Display Port, Full Height
0JHRJ - Graphics Card, NVIDIA Quadro K2000, PCIe, 2 GB, 1 DVI-I, 2 Display Port, Full Height

You can refer below links for various requirement for connecting GPU on R720 and instructions to install GPU.

https://www.dell.com/support/manuals/en-in/poweredge-r720/720720xdom/gpu-card-installation-guidelines?guid=guid-268578e4-b96b-43ba-ac13-58c567cbb670&lang=en-us

https://www.dell.com/support/manuals/en-in/poweredge-r720/720720xdom/installing-a-gpu-card?guid=guid-244e9d21-fbb7-4246-9602-4d85e5cab508&lang=en-us 

Hi, 

I have to change it with 1100 W PSU? -> yes this is recommended.

Thank you for your detailed answer.
Those 2 models you have suggested are not listed for encoding.

I will need to install quadro GPU from this list for encoding: https://developer.nvidia.com/video-encode-and-decode-gpu-support-matrix-new

Most of them are M or P series of quadro, but M I can not use because it can not encode H.265, so maybe models of quadro like P2000, P2200, P4000 ... ?

It will be very helpfull if there is a list of compatible GPU-s for DELL Poweredge R720.

Thank you.

Hello Vangel,

We show a list of Supported GPU cards Pages 36-37  Technical Guide : https://downloads.dell.com/manuals/all-products/esuprt_ser_stor_net/esuprt_poweredge/poweredge-r720_reference-guide_en-us.pdf

Also reference Page 22 GPU Card Installation Guidelines:

Among the information listed there, please note: All GPU cards must be of the same type and model.