[sp332]

When the PS3 first came out, they were having really bad yield issues. The design of the chip is one slowish "normal" processor, plus 6 "synergistic processing elements" which were really fast little vector processors. Well, not exactly 6... If you look at the chip http://www.trustedreviews.com/Sony-PlayStation-3_Games_revie... you'll see 8! OK so one was reserved by the OS for a hypervisor that would run in the background all the time and was not available for mere mortals to access. But that still only explains 7. Turns out they just disabled one of the SPEs. They tested each of them and if one happened to be broken, they would pick that one to be disabled. This N+1 redundancy improved effective yields even though a lot of the chips were still broken!