Emulation still has a long way to go, with emulating the 7th generation of consoles still not being a flawless endeavor and then the 8th being beyond reach for now, however RPCS3 is leading the charge in terms of PlayStation 3 emulation. Recently they made headlines by making The Last of Us and Red Dead Redemption run on PC, albeit at single-digit framerates, but a new update has made better performance possible.
The dev teams working on RPCS3 are constantly refining the code and optimising the software, and two days ago they achieved something of a small breakthrough. A number of SPU recompiler improvements implemented by one of the team members, Nekotekina, means the emulator can now provide better performance across a number of games. Demon's Souls was used to demonstrate the improvement.
The three-minute demo, showing gameplay from high-intensity areas like Boletarian Palace and Tower of Latria show the game running at a mostly stable 30 FPS at 4K resolution. The PC used for the demonstration uses a 4.3 GHz i7-6700k CPU, and is the same machine that struggled to hit 20 FPS in these areas prior to the upgrade. Technically, this is the same performance that an actual PlayStation 3 would deliver.
There are still some challenges to tackle before 7th gen emulation becomes a truly convenient and enjoyable method of playing games, as there is still the shader cache issue for RPCS3, and this performance update doesn't automatically mean that all games will run at a solid 30 FPS, not to mention that not all gamers have access to a CPU strong enough to pull this off. In any case, it's an exciting breakthrough, and shows how far emulation has come.