Optimization and design of high radix asymmetric crossbar
Yongqin Wang · Computer Engineering and Science · 2013
Head-of-line(HOL)blocking limits the throughput of high radix switches.An efficient architecture,OE-ASC,is proposed for high-radix switches.This architecture takes advantages of two cost-effective strategies for dealing with the HOL blocking problem.The first is referred to as asymmetric crossbar(ASC),through which a N×Nswitch can be formed by N/msmaller m×Nasymmetric crossbars,and the second is odd-even queues scheme,through which the resources(mainly memory queues)of the switch can be used more efficiently.A tile-based microarchitecture of 32×32 high radix switch is proposed.Clock cycle-accurate simulation shows that the impact of HOL blocking is nearly all eliminated and the switch throughput can be as high as 98.6%.The proposed OE-ASC architecture shows up to 7.9% of throughput over ASC with buffer depth 16,and can achieve comparable performance with half buffers.