PERFORMANCE CONSIDERATIONS OF SHARED VIRTUAL MEMORY MACHINES

Generalized speedup is defined as parallel speed over sequential speed . In this paper the generalized speedup and its relation with other ex isting performance metrics, such as traditional speedup, efficiency, s calability, etc., are carefully studied, In terms of the introduced as ymptotic speed, we show that the difference between the generalized sp eedup and the traditional speedup lies in the definition of the effici ency of uniprocessor processing, which is a very important issue in sh ared virtual memory machines, A scientific application has been implem ented on a KSR-1 parallel computer. Experimental and theoretical resul ts show that the generalized speedup is distinct from the traditional speedup and provides a more reasonable measurement, In the study of di fferent speedups, an interesting relation between fixed-time and memor y-bounded speedup is revealed. Various causes of superlinear speedup a re also presented.