The design of the Georgia Tech Time Warp (GTW, version 2.0) executive for cache-coherent shared-memory multiprocessors is described. The programmer's interface is presented. Several optimizations used to efficiently realize key functions such as event list manipulation, memory and buffer management, and message passing are discussed. An efficient algorithm for computing GVT on shared-memory multiprocessors is described. Measurements of a wireless personal communication services (PCS) network simulation indicate the GTW simulator is able to sustain performance as high as 335,000 committed events per second for this application on a 42-processor KSR-2 machine.