Event: OCP Virtual Summit 2020; Speakers: Casey Morrison & Pulkit Khandelwal
Abstract: This presentation explores the signal integrity challenges of PCIe 5.0 and the corresponding OCP system design challenges, where the right balance must be found between PCB materials, connector types, and the use of signal conditioning devices for practical compute topologies: CPU-to-AIC with one/two connectors, JBOG accelerator module baseboard, etc. Each topology has multiple factors impacting SI—package, channel insertion/reflection loss, and crosstalk—requiring tradeoffs between physical channel length, interconnect solution, PCB design/material, etc. Through an objective analysis using open-source tools, the goal is to provide the audience with a step-by-step methodology to optimize their topology between low-loss PCB material, alternative connectors, signal retimers, or some combination thereof. Finally, to improve link uptime and maximize the potential of PCIe 5.0 throughput and latency, we explore the relationship between Lane BER and Link stability.