Rpi 4 poor performance on 4K TV

johndoe348

I get awful frames and lag in emulationstation and psx roms on my 4K TV at any resolution. I've set the resolution of rpi in /boot/config.txt to several hdmi_mode including 480,720, 1080. At lower resolutions emulationstation is more responsive, but doesn't make a difference for psx roms. I've also modified retropie_setup.sh resolutions and set 4kp60=0.

When I connect a 7" 800x480 touchscreen via ribbon cable, everything runs smoothly regardless of what the resolution is set to.

I've added these to my config:

over_voltage=4

arm_freq=1950

gpu_freq=600

v3d_freq=750

BIOS = scph1001.bin

emulator = lr-pcsx-rearmed

TV is set to game mode

I've monitored the cpu speed and it doesn't drop below 1950000

Followed this guide to install: https://github.com/RetroPie/RetroPie-Setup/wiki/Manual-Installation

VictimRLSH

Has pcsx-rearmed been optimized for the Pi 4's GPU? You could be missing out on a HUGE performance boost if the CPU has to do all the heavy lifting for a 4K output...

mitu

There might be a bug in RetroArch which picks the first resolutions offered by the display instead of the current resolution. If the first resolution is 4k@30fps, you'll see it as a slowdown.

You can check the resolution picked by RetroArch by running with verbose logging enabled from the Runcommand launch menu and then looking into /dev/shm/runcommand.log (which you can upload to pastebin.com if you want us to take a look at it).

You can forcibly disable the 4K resolutions by modifying config.txt on the boot partition and adding

[hdmi:0]
hdmi_max_pixel_freq=200000000

[hdmi:1]
hdmi_max_pixel_freq=200000000

(Ref: https://www.raspberrypi.org/forums/viewtopic.php?f=29&t=255970&p=1561266)

squanto

@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