Howto : Major performance boost on Retroarch-based emulators

bilu

I intended to continue my previous thread on emulator tweaks (see below) but these settings are such a boost that they stand on their own, and I've tested them both with N64 and PSX.

Goldeneye and Conker's Bad Fur Day are really smoother now with very few slowdowns (combined with tweaks from my previews threads linked below).

Benchmarks
Conker's Bad Fur Day : 14 fps with the intro rain, 22 fps standing on the rock above the waterfall, full 29.97 fps near the Nasty/Nice sign on second stage, 24-29 fps during the scientist and bee intros.

Goldeneye : 58.83 fps when you start mission, drops to 38 fps during the shooting after the tunnel but then stable at 59.83fps.

Did most testing on PSX with Moto Racer, reports a constant 59.98 fps but I paid more attention to the actual responsiveness. Same results with Tekken 3.

Settings
Select-X (Quick Menu) > Back > Right once, select Audio > Output
change the Audio driver to SDL2 (all options use less CPU than alsathread, SDL2 has the less audio and gameplay lag)

Back > Resampler
leave Resampler as sinc, change Quality to lowest (noticeable performance improvement)

Back twice > select Video > Synchronization
Vsync : On
Vsync swap interval : 1
Frame Delay : 0
Hard GPU Sync : On
Hard GPU Sync Frames : 2
Max swapchain images : 4
Sync to Exact Content (G-Sync, Freesync) : off (not tested, might work well on supported monitors/TVs)

Caveats (still worth it given the major performance boost)

doesn't work well with shaders
disables bilinear filtering on some emulators

Saving changes
For all changes done through the Retroarch menu using Select-X you need to save them using overrides:
Select-X ( or back to Quick Menu) > Overrides > Save Content Directory Overrides (or Game Overrides if specific changes to one game)

Display FPS counter
Select-X ( or back to Quick Menu) > Back > Right once, select On-Screen Display > On-Screen Notifications
On-Screen Notifications : on
Display Framerate : on

Note: several of these changes require starting the emulator again. But for the FPS counter you can just Select-X and return to game without saving if you don't want it permanent.

My other relevant threads
https://retropie.org.uk/forum/topic/27429/howto-emulator-performance-tweaks-for-psp-and-n64-and-quality-for-psx
https://retropie.org.uk/forum/topic/27428/howto-change-output-resolution-to-720p-on-libretro-retroarch-emulators
https://retropie.org.uk/forum/topic/27430/howto-optimized-boot-config-txt