The performance of three directory-based cache- coherence protocols; strict request-response, intervention forwarding and reply forwarding are evaluated via simulation on the SOME-Bus, which is a fiber-optic interconnection network supporting DSM. The simulated system contains 64 nodes, each of which has a processor, cache controller, directory controller and output channel. Simulations have been conducted for each protocol to measure average processor utilization and average network latency for varying values of DSM parameters such as the ratio of the mean channel service time to mean thread run time (T/R), probability of a cache block being in modified state {P(M)}, the fraction of write misses {P(W)} and under different traffic patterns. The results reveal that the performance of all protocols decreases under all traffic patterns as P(W), P(M) or T/R increases. The effect of P(W) on the performance of the protocols reduces as P(M) increases. Reply forwarding performs the best for high P(M) values, intervention forwarding yields the best performance for low P(M) and high P(W) values and strict request-response is the best protocol under hot-region (HR) traffic.

This book constitutes the thoroughly refereed post-conference proceedings of the 7th TPC Technology Conference on Performance Evaluation and Benchmarking, TPSTC 2015, held in conjunction with the 40th International Conference on Very Large Databases (VLDB 2015) in Kohala Coast, Hawaii, USA, in August/September 2015. The 8 papers presented together with 1 keynote, and 1 vision paper were carefully reviewed and selected from 24 submissions. Many buyers use TPC benchmark results as points of comparison when purchasing new computing systems. The information technology landscape is evolving at a rapid pace, challenging industry experts and researchers to develop innovative techniques for evaluation, measurement and characterization of complex systems. The TPC remains committed to developing new benchmark standards to keep pace, and one vehicle for achieving this objective is the sponsorship of the Technology Conference on Performance Evaluation and Benchmarking (TPCTC).