Sun Java System Web Server 6.1 SP11 Performance Tuning, Sizing, and Scaling Guide

Memory

As a baseline, Sun Java System Web Server requires 64 MB RAM. Multiple CPUs require at least 64 MB per CPU. For example, if you have four CPUs, you should install at least 256 MB RAM for optimal performance. For high numbers of peak concurrent users, also allow extra RAM for the additional threads. After the first 50 concurrent users, add an extra 512 KB per peak concurrent user.