Ok this might also be the reason why Muppen 64 runs Fullscreen (and i had some issues on my Pyra to let it run because i missd some packages, ), its also OpenGL ^^ , but the Playstation Emulator only in Maximised Window Mode (Which is also at least most of the Screen)..
But even whitout OpenGL and SDL , the PCSX Runs quite decend, i think i should activate the FPS Meter of the Emulators, and the Mate System Diagnostic Software (that shows how many ram is used etc), to show how many power they need yet.. ^^
The fullscreen problem from before is sorted, it now launches fullscreen on the Pyra. It was because it doesn't launch fullscreen on the Pyra if you just pass in the fullscreen flag to the window creation call, you have to call the function afterwards to explicitly make it fullscreen. Unlike on desktop where it goes fullscreen from just the flag.