I've connected my laptop(Windows 10) with the TV using an HDMI cable. The resolution of the laptop is 3840x2160 and the refresh rate 60Hz.
The TV's resolution is automatically set as 3840x2160 also, but the refresh rate shows 30Hz. 
I cannot change the refresh rate to a higher rate, because the option is not available. 
Now, when I change the resolution of the TV to 1920x1080, I'm able to change the refresh rate to 60Hz.
Why can't I put the resolution as 3840x2160 and the refresh rate at 60Hz for the TV? Does the issue have to do with the HDMI cable, or Windows?
My TV's max refresh rate is 120Hz. Supposedly I should get that option also, but it's not showing there.
1 Answer
Your display is Intel UHD Graphics 620 which can (quote):
Support for up to three independent displays via HDMI 1.4, DisplayPort (DP) 1.2, an Embedded DisplayPort (eDP) 1.4 interfaces.
Your display adapter can then only go up to HDMI 1.4, where I quote from Wikipedia:
HDMI 1.4 added support for 4096 × 2160 at 24 Hz, 3840 × 2160 at 24, 25, and 30 Hz, and 1920 × 1080 at 120 Hz.
This is why you have to choose between 4K resolution and refresh rate, but cannot have both at such high values.
There is no solution for this problem that does not include upgrading your display adapter.
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