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→Emulation issues: extra info for SPU and RSX emulation
There are two major bottlenecks at play:
* '''[[wikipedia:Cell_(microprocessor)|Cell Broadband Engine]]''' - consists of two architectures that developers have to program for; PowerPC, and... whatever the SPEs really are; and you have a great formula for high system requirements, SPU hardware environment is the furthest thing from a PC processor. The RPCS3 developers using ahead-of-time recompilation using LLVM.RPCS3 is not just compiling the code it runs, it's also need to compile a realtime environment simulator e.g the 128x128bit register file, LS sram, the very weird memory flow controller, etc.[https://discord.com/channels/272035812277878785/272083901277667342/1200171144603512892]
* '''[[wikipedia:RSX_Reality_Synthesizer|RSX (Reality Synthesizer)]]''': The [[PlayStation 4 emulators|PlayStation 4]] also went unemulated for a long time, simply because of how many components were just undocumented. The same thing applies here; the [https://www.psdevwiki.com/ps3/RSX RSX unit] is a custom-designed chip developed by NVIDIA specifically for the PS3 and share similarities with GeForce 7800 GTX or G70/G71. It's not well-documented, and developers have to figure out how it displays graphics and graphical effects. Without access to Nvidia's resources, which would normally be included with an SDK, this would be very difficult.
:Something of note is that this GPU was also managed by two different memory units with very disparate frequency speeds; 1) 256 MBs of GDDR3 RAM clocked at 650 MHz with an effective transmission rate of 1.4 GHz, and 2) up to 224 MBs of the 3.2 GHz XDR main memory via the CPU (480 MBs max).
:There is no API, just raw hardware register modifications. Even if you had the source code, you cannot compile it to x86 directly and have it work because of how the target hardware works. So you'd also need an emulator for an NVIDIA G70 in there.
For more information about PlayStation 3 hardware and reverse engineering;
