Time Constrained Scaling
Execution time is kept fixed as system scales
- User has fixed time to use machine or wait for result
Performance = Work/Time as usual, and time is fixed, so
How to measure work?
- Execution time on a single processor? (thrashing problems)
- Should be easy to measure, ideally analytical and intuitive
- Should scale linearly with sequential complexity
- Or ideal speedup will not be linear in p (e.g. no. of rows in matrix program)
- If cannot find intuitive application measure, as often true, measure execution time with ideal memory system on a uniprocessor (e.g. pixie)