The NVIDIA GTX 960 from 2016 has the Maxwell architecture, and NixOS
suggests using the proprietary driver for older than Turing:
> It is suggested to use the open source kernel modules on Turing or
> later GPUs (RTX series, GTX 16xx), and the closed source modules
> otherwise.
Reviewed-by: Aleix Boné <abonerib@bsc.es>
