How to connect processors...
•Tradeoffs:
–close
coupling to minimise delays incurred when processors interact
–separation to
avoid contention for shared resources
•Result:
–spectrum of
alternative approaches based on application requirements, cost, and packaging/integration
issues
•Currently:
–just possible
to integrate 2 full-scale CPUs on one chip together with large shared L2 cache
–common to
link multiple CPUs on same motherboard with shared bus connecting to main memory
–more
aggressive designs use richer interconnection network, perhaps with cache-to-cache transfer capability