Difficulties in Simulation-based Evaluation
Two major problems, beyond accuracy and reliability:
- Cost of simulation (in time and memory)
- cannot simulate the problem/machine sizes we care about
- have to use scaled down problem and machine sizes
- how to scale down and stay representative?
- Huge design space
- application parameters (as before)
- machine parameters (depending on generality of evaluation context)
- number of processors
- cache/replication size
- associativity
- granularities of allocation, transfer, coherence
- communication parameters (latency, bandwidth, occupancies)
- cost of simulation makes it all the more critical to prune the space