@ Cueil
Assuming that all the SPEs run at 3.2ghz
Which they do.
each can pull off on thread
One hardware thread or as many software threads you require (but with less efficiency). You are misinformed about what the SPUs can do.
two of them general purpose threads
You can run anything you like on them (provided you style your code to suit the SPE). They are used for general purpose workloads, like developers have stated they should be used for nearly all the game engine code running on the PS3 in the future. So devs have moved over functions to SPEs step by step (including GPU functions).