Just bought a ViewSonic vx2758-c-mh 1080p 144hz display. The specs claim that it only supports 144hz over HDMI, and I am using the supplied HDMI cable from the box, but highest refresh rate I can achieve is 120hz. Graphics card is an r9 380 (which has HDMI 1.4), and I've tried setting 144hz manually in AMD's drivers but it just says the display doesn't support the selected resolution. I've also downloaded the drivers for the monitor from Viewsonic's website, although they don't seem to appear in device manager, it only comes up as Generic PnP Monitor. 120hz is fine but I'd like to get the most out of the monitor if I can. Do I need to get a DisplayPort to HDMI cable or am I just missing something?