San Andreas is a heavy game. To avoid lag:
After downloading the GTA: San Andreas PSP ISO, move it to a folder on your Android device, preferably in a location that's easily accessible by the emulator. Gta San Andreas Psp Iso Download For Android
If you want to play a legitimate GTA game on a PSP emulator for Android, these were officially released and are fully compatible: GTA: Vice City Stories GTA: Liberty City Stories GTA: Chinatown Wars For the true San Andreas San Andreas is a heavy game