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

@quicksilver The stable build works fine but it has the menu bug. It's definitely something the dev changed.

@tiffanitza I had exactly the same issue. I could edit the controller config in redream and assign a button to exit the emulator but it only worked once. When I went back into redream the button was set back to none. I ran the command chmod 777 /home/pi/RetroPie/BIOS/dc/dc_boot.bin and chmod 777 /home/pi/RetroPie/BIOS/dc/dc_flash.bin

Now when the button is set and I exit redream it is saved. Works every time now and even after reboots and power downs.

@retropieuser555 said in Redream Dreamcast Pi3b+:

I guess there's no experimental way to update to opengl 3 on the pi3?

The PI3's GPU doesn't support (hardware wise) OpenGLES3, there's no 'update' that would fix that.

@mitu true. I'll adjust the flags when I next work on retropie.

Oh, yeah, forgot it's using $md_inst for user data.

@akamming I’m in the same boat as you as far as running an ipac2 in redream. I can’t seem to configure my input for more than one controller per port. Can you please walk me through how to get it up and running. I did read what you did for a workaround but I’m pretty new to the raspberry pi and found it a little hard to understand. Thanks in advance!

@XD3l
I think it is opengl support, while the graphics device may have opengl 3.3 capability the drivers and support from intel make it null. The same is reflected in linux. There is a OpenGL2 workaround in the second link, I haven't tried this yet.
https://retropie.org.uk/forum/topic/21781/ubuntu-retro-support-please

https://retropie.org.uk/forum/topic/21793/ubuntu-18-04-reicast-not-launching-games/17

https://www.intel.com/content/www/us/en/support/articles/000005524/graphics-drivers.html

http://realtech-vr.com/admin/glview