I have the LG 29UB55-B monitor which has a 60hz refresh rate, but I'm wondering if HDMI is cutting it down to 50. I've heard that HDMI only supports up to 1080p resolutions at 60hz and at a higher resolution like 2560x1080 ultrawide the refresh rate drops to 50. Can anyone provide some insight on this? I don't want to buy a displayport cable if I don't need it. Thanks!