PS5SX2 is a port of the PCSX2 emulator built to run natively on a jailbroken PlayStation 5. According to the project’s GitHub repository, PCSX2’s recompilers run on the console’s CPU while a modified version of the ps5vk Vulkan layer handles rendering. The project supports up to 6x the PS2’s native resolution for 4K output, though its README warns that some games are too demanding for 6x scaling on a standard PS5.
Tom’s Hardware reports that the emulator’s physical-disc support covers PS2 games released on DVD through the PS5’s built-in drive or an external USB optical drive. The PS5’s built-in optical drive cannot read CD-based PS2 games because it lacks the laser needed to read CDs.
The same report says developer Sword confirmed that PS3 disc support is planned for an RPCS3 port. That remains a future feature, not something PS5SX2 currently provides. The GitHub project also says PS5SX2 is independent and is not affiliated with or endorsed by Sony or the PCSX2 team.