King_V
Posts: 2
Joined: Sat Sep 26, 2020 8:51 pm

Pi 4 B - Only 30Hz refresh? 3840x1600 resolution, Acer XR382CQK monitor

Sat Sep 26, 2020 9:00 pm

So, I installed Raspbian for the Pi 4, I've had it for a few months, but never quite done much with it yet. My monitor has a native resolution of 3840x1600, and a FreeSync range of 48-75, regardless of whether it's via HDMI or DisplayPort.

The HDMI cable I am using was originally on another computer that was displaying 3840x1600@60 with no problems.

Recently, I tried to actually poke into a few details. However, I've noticed that when I check the display settings, it showed that it was correctly running 3840x1600 resolution, but indicated that it was running at a refresh of 30Hz, with no option to increase it.

Is there something I'm missing here? How do I get this to work at 60Hz?

User avatar
UbuntuWizard
Posts: 62
Joined: Sat Sep 26, 2020 3:52 pm

Re: Pi 4 B - Only 30Hz refresh? 3840x1600 resolution, Acer XR382CQK monitor

Sun Sep 27, 2020 5:26 pm

Thats... a pretty weird resolution for the RPi.
Maybe https://www.raspberrypi.org/documentati ... t/video.md will answer your question on this resolution
I use Ubuntu Linux!

rhildinger
Posts: 39
Joined: Thu Jun 09, 2016 6:07 pm

Re: Pi 4 B - Only 30Hz refresh? 3840x1600 resolution, Acer XR382CQK monitor

Sun Sep 27, 2020 6:05 pm

Have you enabled 4kp60 support yet? The pixel clock for 3840x1600x60hz is too high for the HDMI 0 port without that option being set.

King_V
Posts: 2
Joined: Sat Sep 26, 2020 8:51 pm

Re: Pi 4 B - Only 30Hz refresh? 3840x1600 resolution, Acer XR382CQK monitor

Mon Sep 28, 2020 7:47 pm

rhildinger wrote:
Sun Sep 27, 2020 6:05 pm
Have you enabled 4kp60 support yet? The pixel clock for 3840x1600x60hz is too high for the HDMI 0 port without that option being set.
(insert facepalm here) . . I didn't know that was a thing. I did a quick search, and found I had to do this with raspi-config. Easy peasy, and, before I rebooted, I swear I muttered out loud "It can't be THAT easy, can it?"

It was. Thanks! I had no idea this had to be turned on separately.


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