For the Amiga emulator PSPUAE? I don't have any information on the percentage, but out of the 20 or so games I have tried, 2 didn't run and one was quite slow. The rest ran fine and were near 100% speed most of the time. Some such as Swiv do slowdown a bit when more activity is on screen, and I estimate it slows to about 85-90% speed which is still fully playable. And with sound disabled there is no slowdown at all.How many games are able to be emulated at this time?
As for SNES emulation, I've yet to find any games thet do not run perfectly and at full speed!
Some of the other emulators are also really good.
Even the Nintendo 64 PSP emulator is coming along well. It is still in development, but can already run commercial games, all be it slowly at the moment, but it will improve.
Most PSP games come with a version of the official Sony Firmware, but whatever you do, do not run the updater on any of your game's discs or it will upgrade your PSP back to a version that cannot run ISOs, homebrew and emulation.Did you know that either B-boy or Lumines has the firmware update for 2.7.1?
Some newer games need a newer version of the PSP firmware or they refuse to load, which is where the Dark_AleX firmware is so good because it is based on firmware 3.03 so will run everything currently released for the PSP. Also if you leave the no-UMD option disabled in the boot menu and instead just leave any game disc in the PSP all the time then pretty much all PSP games will boot from ISO images. I've tried a lot of game ISOs on the PSP and they have all worked, including the more recent releases such as Tekken or Lego Star Wars II