The UNIX system: The evolution of UNIX system performance

Performance has motivated much of the change in the UNIX??? operating system over the years. This paper gives the results of measurements of system performance taken over time and links the measured improvements to the algorithmic changes that gave rise to them. The most notable improvements have occurred in methods for performing table searches, disk input/output, and terminal handling; these have been driven heavily by the release from address space and memory restrictions in recent 32-bit hardware. Overall, the changes on 32-bit machines have yielded a more than 25-percent improvement in the system's ability to support time-sharing users.