A Performance Evaluation of Operating System Emulators

The concept of simulating one computer architecture on a system with a completely different architecture has existed for nearly as long as computers themselves. This technique, which has come to be known as emulation, is quickly changing the landscape of the world of computing. Technologies such as the Java programming language have brought emulation into the main stream. If this trend is to continue, a better understanding of the factors that affect the performance of emulated systems must be developed. This information will provide the basis on which future systems will be built. In order to understand the performance characteristics of various emulator implementations, this thesis presents a comparison of the interpretive and dynamic recompiling microprocessor emulation techniques. These emulation technologies are studied through the examination of two implementations of an emulator designed to run binary applications written for Microsoft’s Windows operating system on Apple Computer’s Mac OS X operating system. Using tests which focus on three main areas of emulator architecture, a detailed study of the factors which have the greatest effect on overall emulator performance is presented. The goal of this study is to identify the main bottlenecks in these current emulators, thus providing a focus for the improvement of future implementations. Emulated systems are highly complex, and many of the components from which