I have recently installed a nVidia Tesla K80 graphics accelerator into an existing dual-socket workstation running Ubuntu 20.04 with a low-energy consumption nVidia Quadro NVS315. After updating the nVidia drivers (from legacy 390 that were needed for the Quadro to 450 in order to support CUDA on the K80), the now unsupported Quadro is stuck at a resolution of 640x480, leaving me unable to use xrandr to introduce additional custom resolutions. I have already asked the friendly folks at nVidia and they have confirmed that it is indeed a driver issue (as the Quadro is a legacy GPU by now) and that it is not possible to use two different nVidia drivers in parallel.
I have also tried to use Nouveau but I was unable to turn it on only for the Quadro in "Software & Updates/Additional Drivers", all the entries apart from "Continue using a manually installed driver" are greyed out for the Quadro if the nVidia-proprietary 450 driver is activated for the Tesla. If I switch both devices to Nouveau I have the full resolution but I can't run code on the Tesla.
As it is close to impossible to code on 640x480, I would like to ask if there is a way to force the Quadro running on the manually installed drivers to use a higher resolution or if I can force Ubuntu to use Nouveau only for the Quadro, while using the 450 drivers for the Tesla. Any hints are appreciated.
Thanks for taking your time. :)