Dealing With Contention hard
The Universal Scalability Law extends Amdahl's Law by removing the assumption of:
- A Linear Coherency Cost. Amdahl's Law accounts for serialization (sigma). USE accounts for 'Crosstalk' (kappa) - the N-squared communication cost required to stay consistent.
- B Infinite Memory.
- C Single Core.
- D Network Latency.
Answer: A. Linear Coherency Cost. Amdahl's Law accounts for serialization (sigma). USE accounts for 'Crosstalk' (kappa) - the N-squared communication cost required to stay consistent.
Contention (Amdahl) limits speedup. Coherency (USL) causes *retrograde* scalability (adding nodes makes it slower).
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