Best Possibly Settings for 1080p

[GuilhermeGS2]

It'll depend mostly on the game you're playing. But basically you'll need to at least set the rendering resolution to 4xPSP, which will make the game run with internal resolution of 1920x1088. You can also tweak the texture scaling and filtering settings, but don't expect a miracle, the only way to actually have high resolution textures is to make your own custom textures, but the emulator's option will give an improvement over original textures.