So I recently acquired a fairly nice LG smart TV with a 4k resolution which would be great if we could actually use it all with the connected Raspberry Pi, unfortunately, ‘officially’ the Pi only supports up to 1920×1080 @60fps.

But it’s a Pi and it’ll let us try anything we want so let’s make it run at 4k and see how it handles it.

Requirements

• 4k TV to test on
• Raspberry Pi (I’m using the Pi 3 but any should do, although it will affect the end result)
• I’m using Raspbian 9 (Stretch), you’re mileage may vary in older/newer versions
• Sudo access (I think)

How-To Do It

So we’ve got all the requirements and we’ve hooked it all up together, you’re going to need some way to input commands into the Pi and ideally a way to see what you’re doing. I’m going to assume you’ve already done all that though and move ahead.

1. Open the Terminal.
2. Now we want to open the boot config file in a text editor, I’ll demonstrate using Nano to do this.
3. Type ‘sudo nano /boot/config.txt’ then hit enter to open the config file.
4. You’re going to want to scroll to the bottom of this file and add the following lines –
   • Note: config_hdmi_boost may not be required, it was in my case to ensure the screen always came on but it will depend on various factors such as the TV.

1. For an explanation of exactly what these value do, look at the link at the bottom of this post, for now press CTRL + X and then Y to save the changes.
2. Enter ‘sudo reboot’ to do a reboot and all going well the Pi will start up in a 4k resolution with 24 fps. This was good enough for me but I suspect you could potentially run it at a higher FPS if you really pushed it.

Values

The link below provides a good, short description of what each value actually does – https://www.raspberrypi.org/documentation/configuration/config-txt/video.md