1. Presented by Eric Wheeler
Cost-Effective Parallel Computing David Wood and Mark Hill University of Wisconsin IEEE Computer 1995
Presented by Eric Wheeler

2. Theme
Obtaining sub-linear speedups when implementing a multiprocessor can still be worthwhile.

3. Balanced Systems Amdahl’s Dictum Converse should be true, too.
For each MIPS of processing power need 1 MB memory.
Converse should be true, too.

4. Formalism
Speedup simply needs to exceed costup to be “cost-effective”

5. Remember Memory…
P = 8 === 3.3 speedup needed.
P = 16 === 5 speedup
P = 32 === 8.6 speedup
Previous views are processor centric. Memory can dominate cost!

6. Generalization
When memory dominates, costups can be much smaller than linear in the number of processors.

7. Takeaways Balanced systems should be a goal.
Speedups do not have to be linear to be effective thanks to the peripheral costs of adding another whole machine.

8. Questions
What should you consider as “cost” when deciding if your project design was effective in light of this paper?
What other things can dominate the cost?
What happens to this theory if memory becomes essentially free (e.g. low power, high density, cheap nanoarrays)?