Gran Turismo PSP Emulation Issues

[LunaMoo]

If a "slowdown" is different in-game when loaded from savestate than in-game, it most likely means that your pc is throttling from the harder to emulate parts or keeps power saving mode from the easier to emulate parts.

You use word "all", when in reality you ment "other games I tried", there are a lot of psp games, many of them are easy to emulate, some are not, the latter will have higher, sometimes much higher requirements and most popular games are among those and will require more powerful hardware.

Also while I have no clue about this particular game game, it would be nothing weird for some menus to be more demanding than in-game graphics. 2D graphics is commonly harder to make on modern hardware especially in emulation where nothing is as simple as it looks and s stupid wall could be harder to draw than a complex battle scene.