It's not just the power and capabilities, you also need to license IP (for example, IBM owns the Cell processor from the PS3). In any case, from Sony's point of view it's all about selling new hardware and new games, and you have to see backward compatibility in that light.
So, if you want to play PS2, you are a Retro gamer, and you'll be one Ebay. Or you'll be buying your games one at a time through some equivalent of the Virtual Console App Store. Retro collecting is a pretty cool hobby anyway...
Emulating instruction sets and architectures can be an IP pitfall, but in case of the PS1&2 that's not a problem (since they are Sony designs and the MIPS instructions are quite old) and cleanroom reverse engineered emulation of instructions is a legal grey zone, but probably safe. Also, Cell is a dead architecture, so I don't think IBM would throw a fuss at it being emulated.
You don't need to emulate the instructions. - There are other ways to approach that horse.
Binary Translation for example, you intercept an instruction and "translate" it into a similar instruction that can be executed by the new host machine.
Emulation is intrinsically wasteful on resources... There is a reason why the Xbox One with it's woeful Jaguar cores is able to emulate the Xbox 360 with an uptick in framerates and frame times.
Are you going to pay the millions and millions needed to emulate the ps3 games? Even a powerful PC has trouble emulating a ps3. Each game would have to be rebuilt basically.
The PC isn't representative of what Sony can achieve, PC is taking the approach of reverse engineering to achieve backwards compatibility. (I.E. Lots of trial and error.)
Sony has the information to build an emulator from the ground up without needing to do any of that, so they can make an emulator with significantly less overhead as an instruction isn't being split up and interpreted as multiple other instructions which results in a corresponding hit to performance.
The problem with PS3 games is the complexity of the CPU and thus the complexity of emulating instructions. I have no doubts the PS5 could run PS3 games judging by it's specs and what kind of PC you need to run RPCS3. The problem would be getting enough games to run perfectly. They could just as well use RPCS3, implement a compatibility list and try to get as many popular titles compatible.
Will they do it? Probably not. But it would net Sony a lot of goodwill.
The complexity of the Cell is a poor excuse, especially as the PS3 emulator is better than the Xbox 360 emulator.
The Cell is actually a little easier to emulate, because it uses so many "simple" low-performing cores which can translate really well to many-core powerful PC's, it was hard for developers to build games for, but it's actually a benefit to emulation.
Last edited by Pemalite - on 16 June 2020