Title
SCOC: High-radix switches made of bufferless clos networks
Abstract
In today's datacenters handling big data and for exascale computers of tomorrow, there is a pressing need for high-radix switches to economically and efficiently unify the computing and storage resources that are dispersed across multiple racks. In this paper, we present SCOC, a switch architecture suitable for economical IC implementation that can efficiently replace crossbars for high-radix switch nodes. SCOC is a multi-stage bufferless network with O(N2/m) cost, where m is a design parameter, practically ranging between 4-16. We identify and resolve more than five fairness violations that are pertinent to hierarchical scheduling. Effectively, from a performance perspective, SCOC is indistinguishable from efficient flat crossbars. Computer simulations show that it competes well or even outperforms flat crossbars and hierarchical switches. We report data from our ASIC implementation at 32 nm of a SCOC 136×136 switch, with shallow buffers, connecting 25 Gb/s links. In this first incarnation, SCOC is used at the spines of a server-rack, fat-tree network. Internally, it runs at 9.9 Tb/s, thus offering a speedup of 1.45 ×, and provides a fall-through latency of just 61 ns.
Year
DOI
Venue
2015
10.1109/HPCA.2015.7056050
HPCA
Field
DocType
ISSN
Scheduling (computing),Latency (engineering),Computer science,Clos network,Parallel computing,Radix,Real-time computing,Application-specific integrated circuit,Ranging,Big data,Speedup
Conference
1530-0897
Citations 
PageRank 
References 
8
0.53
18
Authors
5
Name
Order
Citations
PageRank
Nikolaos Chrysos1608.56
Cyriel Minkenberg239939.21
Mark Rudquist380.53
Claude Basso4626.85
Brian Vanderpool580.53