Quick Menu > Options (inside the retroarch Menu (hotkey + B ) into the PSX core (in game)
Enhanced resolution (slow), Enhanced resolution Speed hacks, Enable interlacing are not available.
In recalbox raspberry pi, is available this options... do you know why?
Intel x86 doesn't have the NEON graphics plugin any longer. It was very buggy and unlikely to be fixed.
How could I improve the graphics and textures of the psx games?
Change the emulator.
The other emulator have an option to change resolution to 1x native, 2x native and more options.