Firefly: Illuminating future network-on-chip with nanophotonics

Yan Pan*, Prabhat Kumar, John Kim, Gokhan Memik, Yu Zhang, Alok Nidhi Choudhary

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference contribution

334 Scopus citations


Future many-core processors will require high-performance yet energy-efficient on-chip networks to provide a communication substrate for the increasing number of cores. Recent advances in silicon nanophotonics create new opportunities for on-chip networks. To efficiently exploit the benefits of nanophotonics, we propose Firefly - a hybrid, hierarchical network architecture. Firefly consists of clusters of nodes that are connected using conventional, electrical signaling while the inter-cluster communication is done using nanophotonics - exploiting the benefits of electrical signaling for short, local communication while nanophotonics is used only for global communication to realize an efficient on-chip network. Crossbar architecture is used for inter-cluster communication. However, to avoid global arbitration, the crossbar is partitioned into multiple, logical crossbars and their arbitration is localized. Our evaluations show that Firefly improves the performance by up to 57% compared to an all-electrical concentrated mesh (CMESH) topology on adversarial traffic patterns and up to 54% compared to an all-optical crossbar (OP-XBAR) on traffic patterns with locality. If the energy-delay-product is compared, Firefly improves the efficiency of the on-chip network by up to 51% and 38% compared to CMESH and OP-XBAR, respectively.

Original languageEnglish (US)
Title of host publicationISCA 2009 - 36th Annual International Symposium on Computer Architecture, Conference Proceedings
Number of pages12
StatePublished - 2009
EventISCA 2009 - 36th Annual International Symposium on Computer Architecture - Austin, TX, United States
Duration: Jun 20 2009Jun 24 2009

Publication series

NameProceedings - International Symposium on Computer Architecture
ISSN (Print)1063-6897


OtherISCA 2009 - 36th Annual International Symposium on Computer Architecture
Country/TerritoryUnited States
CityAustin, TX


  • Hierarchical network
  • Interconnection networks
  • Nanophotonics
  • Topology

ASJC Scopus subject areas

  • Hardware and Architecture


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