The pmake program uses remote invocation to invoke tasks concurrently. Compilations commonly obtain speedup factors in the range of three to six; they are limited primarily by contention for centralized resources such as file servers. CPU-bound tasks such as simulations can make more effective use of idle hosts, obtaining as much as eight-fold speedup over a period of hours.
Process migration has been in regular service for almost two years, used by over 20 day-to-day users of Sprite for nearly all compilations as well as most simulations. Empirical measurements of migration use over periods of time ranging from a month to a year are presented. These measurements include the overall use of migration (31% of all processing in Sprite was performed using migrations), the availability of idle hosts (71% of hosts were available for migration during the day, with more hosts available at other times), and the correlation between host idle time and likelihood of eviction (evictions were likely only when hosts that had just become idle were used).