I've hooked up a UHD 120hz TV to my PC's RX480 Gpu via a hdmi cable (I don't know which version), but the highest refresh I can set from the display adapter setting is 60hz. OS is windows 10. I have another 1080p 60hz monitor connected to the same gpu so I don't know if that will affect it. Any ideas on how I can use 120hz for my tv monitor?