Another view on parallel speedup

Three models of parallel speedup are studied: fixed-size speedup, fixed-time speedup, and memory-bounded speedup. Two sets of speedup formulations are derived for these three models. One set requires more information and gives more accurate estimation. Another set considers a simplified case and provides a clear picture of possible performance gain of parallel processing. The simplified fixed-size speedup is Amdahl´s law. The simplified fixed-time speedup is Gustafson´s scaled speedup. The simplified memory-bounded speedup contains both Amdahl´s law and Gustafson´s scaled speedup as its special cases. A metric for performance evaluation is proposed