In the first of two articles to be reprinted from CMP sister publication Embedded Systems Design magazine
, EIC Jim Turley offers an overview of the Cell processor, as used in Sony's upcoming PlayStation 3 console.
This comprehensive overview article explains the Cell's advantages and disadvantages in robust technical terms, including this overarching description:
"Cell is based around a single 64-bit PowerPC processor surrounded by eight identical coprocessors. The central PowerPC processor can execute two instructions at a time. That's nice, but not unusual. Intel, AMD, and others also produce dual-issue processors, even 64-bit dual-issue processors. So the heart of Cell is actually--dare we say it--fairly pedestrian...
The real magic of cell lies with its eight "synergistic processor elements," or SPEs, shown in Figure 2. These are specially designed processors created from scratch by the IBM/Sony/Toshiba team just for Cell. They're not compatible with Power or PowerPC code in any way; they have their own distinct instruction set and internal architecture. For most code, and particularly for parallel vector operations, the SPEs do the heavy lifting. Each SPE is identical to its neighbors, and all share the same common bus with the central Power Processing Element (PPE in IBM-speak)."
You can read the full Gamasutra feature on the topic
for plenty more excellent overview from the embedded systems perspective (no registration required, please feel free to link to this feature from external websites).