Yet another workaround:

The standard command with which pcsx is run in Retropie does not always work without errors. Replace it, using the following steps.

Edit /opt/retropie/configs/psx/emulators.cfg so that the command to launch pcsx-rearmed reads:

pcsx-rearmed = "/opt/retropie/emulators/pcsx-rearmed/pcsx -cdfile %ROM%"

A new (hidden) config dir will be created: /home/pi/.pcsx/. And a dir where you must place the the PSX BIOS (i.e. the file SCPH1001.BIN): /home/pi/bios/.

Redo the settings for pcsx. They will be saved in /home/pi/.pcsx/pcsx.cfg. Do NOT copy the file 'pcsx.cfg' from /opt/retropie/configs/psx/pcsx/! You can, however, copy other settings like save files from there.

When certain emulators crash then the command line on my Pi (running Raspbian 9 Stretch) is unresponsive. The Pi does, however, respond via ssh. But no matter what process I kill, the console on my television stays non-responsive. Anybody got some tips & hints?

@dogeymon Good to hear! Also try switching up your emulators if some games aren't working great. If I remember correctly, Pier Solar didn't work well with the default Genesis emulator but when I used a different one, it ran much better. Glad your Genesis isn't ruined :)

I am having this problem too and its really frustrating!

@BuZz I want to disable it for the Nintendo 64 and SNES

@mrgibby yeah i think dispmanx was fixed to respect the swapchain setting, and now the following applies:

Note on video_max_swapchain_images setting
When using the OpenGL ("gl") video driver, this setting switches between using two or three buffers for rendering. Without going into details, a setting of 3 allows the emulator to run ahead and prepare the next frame before the current one has even been shown. This improves performance (i.e. makes framerate hiccups less likely), especially on slow hardware, but increases input lag by one whole frame in the general case.
So, the general rule is to use a setting of 2 if the system can handle it. It will shave off one frame of input lag compared to the default setting of 3. Please also note that a setting of 2 forces vsync on.

i guess in this case the system couldn't handle it :(

@themyst
This may help:
https://retropie.org.uk/forum/topic/2199/specific-retroarch-emulator-settings-are-being-over-written-after-i-quit-the-game/24

@mortosaur for best image quality - try darkplaces quake (h/w accelerated 3d) or lr-tyrquake for libretro core version of the original

ok, thanks

The dispmanx video driver for RetroArch seems to be in somewhat of an unfinished state. I recently switched over to it myself to reduce latency and the first thing I noticed was that the onscreen yellow text was no longer visible. This is such a key element of RetroArch that you can bet the libretro guys aren't through with it's implementation yet. How long it will take to finish it up is anyone's guess and there is always the possibility that it will remain as is, but after switching to a wired controller and dispmanx, I personally believe the trade off is worth it for the more responsive controls. Otherwise beating hyper-sensitive control scenarios like the turbo tunnels in 'Battletoads' would be an impossibility.