The 4.2 Berkeley Software Distribution of UNIX for the VAX has several problems that can severely affect the overall performance of the system. These problems were identified with kernel profiling and system tracing during day to day use. Once potential problem areas had been identified benchmark programs were devised to highlight the bottlenecks. These benchmarks verified that the problems existed and provided a metric against which to validate proposed solutions. This paper examines the performance problems encountered and describes modifications that have been made to the system since the initial distribution. Suggestions for further performance improvements are given.