I had Radeon R9 390 8G I want purchase new monitor 49inch 5120x1440. by my check the gpu not support this resolution.
is this unsopport because the software or the gpu cant to provide this resullostion?
The Radeon R9 390 8G does support 1440p resolution, it handles 1440p gaming pretty good as well.
Just make sure the monitor you get is FreeSync