PANDA: ring-based multiprocessor system using new snooping protocol

The PANDA is a ring-based Cache Coherent Non-Uniform Memory Access (CC-NUMA) multiprocessor system under implementation at the Seoul National University. Its main goal is to ameliorate the data miss latency by using the unidirectional point-to-point interconnection network. We introduce the PANDA architecture and present a new snooping protocol for this system. We evaluate the performance of the PANDA for a small to medium scale multiprocessor system using analytical models and a program-driven simulator. We compare the proposed system to other alternatives of point-to-point connected machines, such as the Express Ring and full map directory based system. The simulation results show up to 29% performance improvement against the Express Ring. They also show that the PANDA performs no worse than the full map directory based system, which has the additional hardware costs for the directory management.