Screen tearing is a issue of the Raspberry Buster Lite that the current RetroPie image is using. The upcoming version i think it will get rid from this issue.

Some users solved this issue, in the current version of RetroPie, after they use the experimental kms driver, but this add other issues. If you search in the forum about screen tearing you will find a lot of info. Also i recommend to read the wiki about the used of 4k TV with Rpi4: https://retropie.org.uk/docs/Pi4/

@mitu sorry I thought I added more to the title. 😣 I'll try those cheers

@mitu Thanks for the suggestion. Tried that already previously but it didn't work, but I will give it another go. I hope the new HDMI cable will fix the issue.

@dankcushions It worked! Thanks. I’m officially on 1080p.

I find even with a pi4 i can't run anything past 1080p, also make sure you have your game mode set on your tv.

I will admit i have not attempted to use advmame yet, so i am just kinda throwing out suggestions.

Hi everyone,

I was able to make it working with:

hdmi_ignore_edid=0xa5000080
disable_overscan=0
overscan_left=0
overscan_right=0
overscan_top=0
overscan_bottom=0
hdmi_force_hotplug=1
hdmi_group=1
hdmi_mode=16
config_hdmi_boost=7

Then I got 60fps in Steam, but no image. After disabling the Nvidia overlay in the Gforce settings I had an image again but heavy framedrops. After setting Bandwidth limitation in Steamlink itself to "Auto" these were gone as well. Now Rayman is running with 60pfs, what results in no speed change of the game. Why the game reacts so badly on not having 60fps I did not found out.

Best regards!

@sonicman2020 with respect, your understanding of the runahead settings, and the audio latency settings are very wrong. if you want to get this working properly, please start again from the retropie image, and don't change such settings: https://retropie.org.uk/docs/First-Installation/

Please do not post a support request without first reading and following the advice in https://retropie.org.uk/forum/topic/3/read-this-first

@Brunnis said in Retro Pi 4.6 - Pi4 /4kTV slow loading:

I seem to remember you can limit the pixel clock instead, but I haven't tried it.

Yes, it's possible, though this will disable the 4k video modes completely.

Also, given the performance issues with 4K, wouldn't it be better to have RetroPie be limited to 1080p max out of the box, with an easy way to enable 4K if the user wishes?

This is exactly what the hdmi_mode/hdmi_group settings do - set 1080p video mode by default, with the ability to choose 4k via runcommand (though performance will not be great). Kodi/Pixel desktop would still be able to use those modes for 4k HEVC movies/normal desktop.

Unfortunately there isn't a way to configure the video so that 'if 4k is available, use 1080p by default', so instead of forcing 1080p by default for all configurations, it's something that the user must configure after installation.

@njsilvestri21 what is the make and model of your tv you are using? Some 4k TV's only support 60hz on one particular HDMI port and some off brands don't support 4k60 at all. But just an fyi, RetroPie performs much better at 1080p.

if it's screensaver / screenblanking shouldn't it happen when other screens are attached as well ? the settings about it do not change when switching screens so in theory he should have the issue on every screen attached then

This is how I fixed laggy N64 performance on my 4K tv:

hit F4
cd /boot
sudo vi config.txt

in config.txt, add the following to force 1080p:

hdmi_group=2
hdmi_mode=82

[hdmi:0]
hdmi_max_pixel_freq=200000000

[hdmi:1]
hdmi_max_pixel_freq=200000000

@mitu This was helpful! But I also had to force 1080p by setting hdmi_group and hdmi_mode:

hdmi_group=2
hdmi_mode=82

For more video mode options see:
https://elinux.org/RPiconfig#Video_mode_options

UPDATE: Thank you guys! Indeed Ubuntu was set to 4K, changed it to 1920x1080 60hz and it instantly solved the issue. Facepalm Rookie mistake! lol! I appreciate everyones help!

@Melvin.FoX The link i provided refers to changes you can make in the boot.txt file. 😉