@mitu That is great information, thanks! I will have a play around with this.

EDIT: Worked like a charm, awesome. I never knew creating a custom shader would be this easy.

The crt-mattias and crt-geom are way too demanding for a Raspberry Pi, they're not installed by default on the Pi - only on a PC installation.

@megaJekan as said in your other thread, 480p is unnecessary for a pi3b+ and pcsx. psx emulation has been running full speed on pis since the pi2. if you're getting slowdown at 1080p and NO shaders, you have a system issue.

as for curvature shaders - zfast should be full speed at 1080p on most games and is the fastest one available. they won't look at 480p as it's just not enough resolution for that effect to look good. it's not enough resolution for a non-curved scanline shader...

I did give a try a few minutes ago. If I sit far away from my TV the shader looks okay but if I'm up close I can tell a difference. I don't know enough about the inner workings of shaders to say exactly why it looks worse up close, but it does. Hmmm.. I guess it's back to 1080p then as a nice shader is more important to me than marginally smoother menus.