The team behind God of War III, Sony Santa Monica, explain that the PlayStation 3's SPU processors are much faster than many developers think they are.
In their GDC '09 keynote, titled Practical SPU Programming in God of War III, Jim Tilander and Vassily Filippov of Sony Santa Monica detailed their use of the PlayStation 3's SPUs.
The Cell processor features one main processor, PPU, and 8 specialist processors, SPUs, one of which is turned off for optimisation reasons, with another used for the PlayStation 3's OS.
In their keynote, Sony Santa Monica explained that the SPUs aren't actually coprocessors but are full general purpose processors that can handle code directly lifted from the PPU. Moreover, they aren't just fast, but they are super fast and with a little bit of help they can run code at unbelievable speeds.
In fact, the God of War III team rely on the SPUs to accelerate both the PlayStation 3's GPU (RSX) and the PPU. They then detailed the systems running on the SPUs, which include animation, cloth, collision, procedural textures, culling, shadows, push buffer generation, meta tasks, geometry conditioning, and sound. Indeed, most (if not all) of the heavy lifting is left to the SPUs.
The team concluded their talk by reiterating that developers must use the parallel nature of the PlayStation 3 and not treat SPUs as a special case, since they are much faster than you think they are.
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