Some additional commentary from a blog analysing the Inq's story:

https://assemblergames.com/threads/ps3-concerns-cell-archite...

«It means that no more than three of the SPE's can talk to the memory controller at one time using full capacity. Four SPE's will fill the bus, and the CPU controller will not be able to access the memory at all.

[...]

What you can do is have all the SPE's work at the same time, but using nowhere near the capacity they each have. Basically the PS3 gets punished for performing well, and tweaking cell for better results in the future seems to be a nightmare if not impossible. »