MP 1,1-5,1 Which video card can I buy for a 2012 Mac Pro to support an ultra wide curved display by AOC?

[EDF]

I am interested in getting this monitor to work properly with a system in my studio. Right now it pushes a max resolution of the 2560x1600 which works but we would like it to look better.

AOC AG493UCX 49 inch monitor | AOC Monitors

AOC AG493UCX 49 inch monitor. 49” ultra-wide curved monitor (32:9) with 120 Hz refresh rate and DQHD resolution

us.aoc.com

It's a 49 inch ultra-wide.

Right now I have the factory ATI Radeon HD 5870 in the system.

Any direction or help is appreciated it.

 

[Flint Ironstag]

Which OS are you running on your Mac Pro? How high past a supported OS are you willing to go?