[SOLVED] PC crashes at 4K @ 120 Hz, can only do 1440p @ 120 Hz; help much appreciated!

[sephirothxt]

Hi all,

I just got a new TV that supports 4K at 120 Hz. It's an 86 inch LG TV. Here's the link

I have an EVGA 3080 Graphics card (10850k Intel CPU, 32 GB RAM). I am also using an HDMI 2.1 cable (here's the Newegg link; it's a company I haven't heard of before, and it has no reviews, but it seemed legit).

I can tell any game (Flight Simulator, Halo MCC) to output at any FPS at 4K, and they all do at least 120 FPS as shown on MSI Afterburner. But that doesn't mean anything unless the nVIDIA control panel is outputting at 4k 120 Hz.

Whenever I change the resolution through the control pantel to 4K at 120 Hz, the PC crashes (sort of). The screen goes blank, and then the TV says that there's no more video input from the computer. I then have to manually shut the computer off and then turn it back on. It doesn't even do that thing where it reverts back to your last settings if you don't click anything within 15 seconds. This link is where I'm going with the nVIDIA control panel.

If I put it on 1440p (2560x1440) at 120 Hz through the nVIDIA control panel then it works. It allows it to function. And to me, the FPS looks better on my games (so I think it's a true 120 Hz). If it makes any difference, my color settings are : Desktop color depth of 32 bit, 8 bpc of output color depth, FULL output dynamic range, and RGB output color format.

Since my GPU and TV are both capable of 4k at 120 Hz, I would really like to take full advantage of this. Any advice, or trouble-shooting I can do to see why I'm getting 1440p at 120 Hz but not 4k at 120Hz when the TV, GPU, and HDMI cable all seem to be right?

 

[boju]

Is tv connected to the internet? Try update firmware for it. I've read a few mentions of firmware updates addressing issues with Nvidia 3xxx series. Could be related, fingers crossed that's all is needed.

 

[sizzling]

This sound exactly like the issue I had with my LG C9 and RTX3080. I had to wait for a firmware update for the TV, it only came out about 10 days ago. I know the update I got was only for OLED’s so you would be looking for a different one.

 

[sizzling]

Looking at the EU version of that TV an update was released 2 days ago. I had to download and install the update using a USB drive as the update wasn’t yet available using the automatic distribution in the TV menu.

 

[boju]

Good point about possibly needing to use usb.

 

[sephirothxt]

Hi all,

Thank you for the tips. I did finally manage to make it work! Though now for some reason I can't turn on HDR with 4k at 120 Hz, but I think I'm okay with that. I still want to figure this out though. But for now I'll count my victory, and thank you guys for the advice

I'm not sure which of the two changes made the difference. The first was updating the LG TV as you all recommended, so thank you for advising that. I didn't need the USB thankfully, just did it over wifi.

The 2nd change which was kind of interesting is that I didn't change the resolution and Hz through the nVIDIA control panel. I went to Windows' SETTINGS app. From there, you click on Display, and it allows you to change the resolution. To change the Hz, you have to click the bottom option which states "Advanced Display settings," and from there you click "Display adapter properties for Display 1." From there, you can click on the monitor tab, and then you can change the screen refresh rate to 120 Hz. When I went this route, it didn't freeze up. And the PC tells me under the Display settings that it's indeed doing 2160p at 120 Hz, as well as the nVIDIA control panel (weird that nvidia's app didn't let me change it, but now that I changed it through Display Settings, it's displaying the reflected setting).

So long story short, I updated the firmware as you guys recommended, and then changed the resolution through the Windows Display Settings, rather than nVidia control panel. The nVidia control panel was weird. After updating the firmware on the LG TV, when I tried to create a custom resolution, it would occasionally allow me to succesfully test a 4k 120 Hz resolution, but it wouldn't let me save that setting. And most of the time it would just freeze up.

I may circle back around to these forums to ask about the HDR thing if I can't figure it out, unless you guys know of some magical solution . The Windows Display settings says that my TV can't stream HDR video, but it can play HDR games and apps. But when I try to click the icon to turn on HDR for games and apps, it briefly switches on before immediately switching off. I'm not sure why. I'll play around with it and my TV settings.