Using a DP-HDMI cable rated to carry UHD (3840X2160 @ 60Hz res), have tried 2x, Insignia 43" UHDs, 1x, TCL, 1x Samsung. None will run UHD @ 60Hz. They either switch to 30 Hz when "save change" or won't run UHD at all (the TCL). However my LG TV does run as monitor @ 60Hz from the same set up. The obvious solution is go get an LG TV for monitor... DUH! But that won't work for me as having 2 LGs in the same room has them both responding to the remote at the same time when only one responding is desired. Any suggestions?
why don't you get a monitor as a monitor? The computer monitor screen size has been getting bigger, image quality getting better and better, and the price is getting very attractive.
Currently, price of a 43" monitor is 2-3 times the cost of 43" TV. Not that I couldn't afford the monitor, but an unnecessary expense.
Update... I looked into this further. Others have mentioned same problem. 1. To get UHD @ 60Hz res, (a) you need DP 1.4 or HDMI 2.0 or better, and the TV's system must be capable of handling it.... problem seems to be with HDR. 2. If TV can't handle it, the res will usually be 3840x2160 @ 30Hz or less.... the TCL wouldn't do even that. 3. The Samsung* obviously cannot handle it either, but my LG (6540?) can and displays properly. (I have DP 1.4... HDMI 2.0 could be different/better??) *The solution in 2018 Samsung models was to "disable HDR", but in my newer model there is no option to do so. FWIW....
I've been using a 55" TV as a monitor for 2 years now. It runs 4k @ 60fps no problem, both on Windows and Linux. I suspect that your issue might be due to the graphics card. If not, then there might be a "PC mode" on the TV which would disable HDR and other processing.
Roughly 3 feet (90cm) from my eyes. I've got it on a standing desk too. The screen is 4K, so it is essentially the same as having four 22.5" 1080P displays without any gaps. Having said that, now I'd probably go for a 43" or a 50" TV.
My 55" LG 6540 does run 4K @ 60Hz, but the Samsung 43" would only run 30Hz. I said "would" because that has changed so that the Samsung now runs @ 60hz also. The way W10 displays the "Display" page has also changed, so I suspect some W10 update is responsible for it. FWIW...