Optically Connected Memory for Disaggregated Data Centers

Jorge Gonzalez; Alexander Gazman; Maarten Hattink; Mauricio G. Palma; Meisam Bahadori; Ruth Rubio-Noriega; Lois Orosa; Madeleine Glick; Onur Mutlu; Keren Bergman; Rodolfo Azevedo

arXiv · 2008.10802

Optically Connected Memory for Disaggregated Data Centers

Jorge Gonzalez·Alexander Gazman·Maarten Hattink·Mauricio G. Palma·Meisam Bahadori·Ruth Rubio-Noriega·Lois Orosa·Madeleine Glick·Onur Mutlu·Keren Bergman·Rodolfo Azevedo

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Abstract

Recent advances in integrated photonics enable the implementation of reconfigurable, high-bandwidth, and low energy-per-bit interconnects in next-generation data centers. We propose and evaluate an Optically Connected Memory (OCM) architecture that disaggregates the main memory from the computation nodes in data centers. OCM is based on micro-ring resonators (MRRs), and it does not require any modification to the DRAM memory modules. We calculate energy consumption from real photonic devices and integrate them into a system simulator to evaluate performance. Our results show that (1) OCM is capable of interconnecting four DDR4 memory channels to a computing node using two fibers with 1.07 pJ energy-per-bit consumption and (2) OCM performs up to 5.5x faster than a disaggregated memory with 40G PCIe NIC connectors to computing nodes.

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Jorge Gonzalez, Alexander Gazman, Maarten Hattink, Mauricio G. Palma, Meisam Bahadori, Ruth Rubio-Noriega, Lois Orosa, Madeleine Glick, Onur Mutlu, Keren Bergman, Rodolfo Azevedo. 2020-08-25. Optically Connected Memory for Disaggregated Data Centers. https://arxiv.org/abs/2008.10802

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