Silicon-photonic clos networks for global on-chip communication

Future manycore processors will require energyefficient, high-throughput on-chip networks. Siliconphotonics is a promising new interconnect technology which offers lower power, higher bandwidth density, and shorter latencies than electrical interconnects. In this paper we explore using photonics to implement low-diameter non-blocking crossbar and Clos networks. We use analytical modeling to show that a 64-tile photonic Clos network consumes significantly less optical power, thermal tuning power, and area compared to global photonic crossbars over a range of photonic device parameters. Compared to various electrical on-chip networks, our simulation results indicate that a photonic Clos network can provide more uniform latency and throughput across a range of traffic patterns while consuming less power. These properties will help simplify parallel programming by allowing the programmer to ignore network topology during optimization.

• Type: Conference
• Year: 2009
• Where: NOCS
• Authors: Ajay Joshi, Christopher Batten, Yong-Jin Kwon, Scott Beamer, Imran Shamim, Krste Asanovic, Vladimir Stojanovic
• Keywords: Clos Network, Computer Networks, NOCS 2009, On-chip Networks, Photonic Clos Network