I have a AMD Radeon R7 200 and a Philips 298x4. The monitor works at a resolution of 2550x1080. The electronics detect are as 1920x1080. How can I fix?
Use a Displayport or HDMI cable and make sure you aren't trying to set too high a refreshrate. Most monitors can only do their highest refreshrate at less than native resolution. At native res the highest your monitor can do is 60Hz.