In this paper we propose the use of an optical network not only as the communication medium, but also as a system-wide cache for the shared data in a multiprocessor. More specifically, the basic idea of our novel network/cache hybrid (and associated coherence protocol), called NetCache, is to use an optical ring network on which some amount of recently-accessed shared data is continually sent around. These data are organized as a cache shared by all processors. We use detailed execution-driven simulations of a dozen applications to evaluate a multiprocessor based on our NetCache architecture. We compare a 16-node multiprocessor with a third-level NetCache against two highly-efficient systems based on the DMON and LambdaNet optical interconnects. Our results demonstrate that the NetCache multiprocessor outperforms the DMON and LambdaNet systems by as much as 99 and 79%, respectively. Based on these results, our main conclusion is that the NetCache is highly efficient for most applicatio...
Enrique V. Carrera, Ricardo Bianchini