@achillespilot Hey- I did get it worked out. What worked for me was lr-mupen64plus-next and video at 1920x1080 @ 60 Hz. The N64 logo when the rom launches looks like garbage but the intro and the game itself look great. Good luck!
was the only option I needed in config.txt to get emulation station to work from hdmi 1.
(I needed to use this as the fat micro hdmi adapter I was using pressed against the usb-c power connector)
These are the only options I have set in config.txt (audio and video on second hdmi port 1 work fine in emulation station)
# OVERCLOCK SETTINGS
arm_freq=1800 # CPU Frequency
gpu_freq=600 # GPU Frequency
over_voltage=2 # Electric power sent to CPU / GPU (4 = 1.3V)
# Enable DRM VC4 V3D driver on top of the dispmanx display stack
What game(s) have you tried? It could be a corrupted ROM, so try a few different games or try to find another copy of the game.
Have you tried to remove the redream package and re-install from the latest binary?
Also have you tried using the lr-flycast or Reicast emulators to run the game instead? Both can be found within the optional packages menu. When launching the ROM, hit a button to choose which emulator to use(once you have installed them). All three emulators run well on my RPI4 4Gb at stock speeds.
Only other thing is to think your pi is throttling, have you any heatsinks/cooling? Are you using a case?