Vita3K requires a copy of the PS Vita system firmware ( PSVitaUpdate.xml and a .pup file) as well as device keys. The emulator’s first-time setup wizard will guide you through extracting these from a legitimate source (or you can find them online, though legality is murky).
Start at 1x (Native) . If you have a powerful device, you can upscale to 2x for sharper visuals. vita3k roms