4K TV Connected to PC Only Running at 720p

[SuperFighterGood]

System: https://pcpartpicker.com/list/7qpXsZ

 

Hi, recently I bought a 4k TV, a Toshiba 50L711U18, and it works fine as a 2nd monitor for my PC. The only problem is, it doesn't actually want to run at 4k (3840x2160), its native resolution. Sure, I can set it to 4k through AMD Settings or through the Windows display settings, but whenever I check it in a game or anywhere, it's as blocky as 720p. And that's what games think it is, 720p. I know my HDMI cable can support 4k, as it's HDMI High Speed, so I don't know what the problem is here. Can anyone help me out?

[Unimaginative Name]

Change the resolution in-game? I have a 1440p monitor and when I load into games for the first time, it is usually set to 720p or something along those lines. You need to change the in-game settings. Windows runs in 4k for you, right?

[avg123]

What is the resolution of your main monitor?

[SuperFighterGood]

1 minute ago, Unimaginative Name said:

Change the resolution in-game? I have a 1440p monitor and when I load into games for the first time, it is usually set to 720p or something along those lines. You need to change the in-game settings. Windows runs in 4k for you, right?

When I do, it jumbo sizes it and it goes onto my second monitor, acting like the monitor is only 1/8 of the size of the actual one.

[SuperFighterGood]

Just now, avg123 said:

What is the resolution of your main monitor?

1440p

[Unimaginative Name]

1 minute ago, SuperFighterGood said:

When I do, it jumbo sizes it and it goes onto my second monitor, acting like the monitor is only 1/8 of the size of the actual one.

I've noticed some games just do that. I usually go full-screen, and then change the resolution. Again, does Windows run in 4K?

[avg123]

disconnect your main monitor and only use tv, See if games run at 4k or not

[SuperFighterGood]

1 minute ago, Unimaginative Name said:

I've noticed some games just do that. I usually go full-screen, and then change the resolution. Again, does Windows run in 4K?

Windows does run in 4K, and running it in fullscreen does the same thing.

[SuperFighterGood]

2 minutes ago, avg123 said:

disconnect your main monitor and only use tv, See if games run at 4k or not

Doesn't work.

[avg123]

1 minute ago, SuperFighterGood said:

Doesn't work.

what dosent work?

[SuperFighterGood]

2 minutes ago, avg123 said:

what dosent work?

Using the TV as the main monitor still has the 720p scaling problem.

[avg123]

do you have a second computer or laptop you can plug in your tv. that would narrow down the source of the problem--- your computer or your tv

[SuperFighterGood]

22 minutes ago, avg123 said:

do you have a second computer or laptop you can plug in your tv. that would narrow down the source of the problem--- your computer or your tv

Sadly, no

[SupaKomputa]

If you can change the tv resolution to 4k in windows, i think you should be able to change it in the game.

Maybe you selected "windowed display", change it to fullscreen.