Increasingly, microprocessor performance is limited by achievable
power dissipation rather than by the number of available integrated-circuit
resources (transistors and wires).
Therefore, the only way to significantly increase the performance of microprocessors
is to improve power efficiency at about the same rate as the performance increase.
One way to increase power efficiency is to differentiate between:
- processors optimized to run an operating system and control-intensive
code, and
- processors optimized to run compute-intensive applications.
The
Cell Broadband Engine does this by providing
a general-purpose PPE to run the operating system and other control-plane
code, and eight SPEs specialized for computing data-rich (
data-plane)
applications.