{"title":"PCI-Express: Evolution of a Ubiquitous Load-Store Interconnect Over Two Decades and the Path Forward for the Next Two Decades","authors":"Debendra Das Sharma","doi":"10.1109/mcas.2024.3373556","DOIUrl":null,"url":null,"abstract":"The Peripheral Component Interconnect Express (PCI-Express or PCle) architecture has been the ubiquitous backbone interconnect in the evolving computing landscape for more than two decades. This paper delves into the multiple innovations driving the backward-compatible evolution of PCle for seven generations, doubling bandwidth every generation, while delivering power-efficient and cost-effective performance. Compute Express Link (CXL) overlays coherency and memory protocols on top of PCle for heterogeneous computing, addressing the memory wall, resource pooling and sharing across servers, and distributed computing using load-store based messaging. The die-todie industry-standard, Universal Chiplet Interconnect Express <inline-formula xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" xmlns:xlink=\"http://www.w3.org/1999/xlink\"> <tex-math notation=\"LaTeX\">$^{TM}$ </tex-math></inline-formula> (UCle), offers orders of magnitude improvement in bandwidth density, power efficiency, and latency for PCle and CXL protocols on-package and pod-level connectivity with co-packaged optics. We foresee PCle will continue to evolve over the next few decades to serve future computing needs. It will do so by embracing alternate media while backward-compatible frequency scaling with copper will continue and protocol enhancements will enable non-tree fabric topologies.","PeriodicalId":55038,"journal":{"name":"IEEE Circuits and Systems Magazine","volume":null,"pages":null},"PeriodicalIF":5.6000,"publicationDate":"2024-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"IEEE Circuits and Systems Magazine","FirstCategoryId":"5","ListUrlMain":"https://doi.org/10.1109/mcas.2024.3373556","RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, ELECTRICAL & ELECTRONIC","Score":null,"Total":0}
引用次数: 0
Abstract
The Peripheral Component Interconnect Express (PCI-Express or PCle) architecture has been the ubiquitous backbone interconnect in the evolving computing landscape for more than two decades. This paper delves into the multiple innovations driving the backward-compatible evolution of PCle for seven generations, doubling bandwidth every generation, while delivering power-efficient and cost-effective performance. Compute Express Link (CXL) overlays coherency and memory protocols on top of PCle for heterogeneous computing, addressing the memory wall, resource pooling and sharing across servers, and distributed computing using load-store based messaging. The die-todie industry-standard, Universal Chiplet Interconnect Express $^{TM}$ (UCle), offers orders of magnitude improvement in bandwidth density, power efficiency, and latency for PCle and CXL protocols on-package and pod-level connectivity with co-packaged optics. We foresee PCle will continue to evolve over the next few decades to serve future computing needs. It will do so by embracing alternate media while backward-compatible frequency scaling with copper will continue and protocol enhancements will enable non-tree fabric topologies.
期刊介绍:
The IEEE Circuits and Systems Magazine covers the subject areas represented by the Society's transactions, including: analog, passive, switch capacitor, and digital filters; electronic circuits, networks, graph theory, and RF communication circuits; system theory; discrete, IC, and VLSI circuit design; multidimensional circuits and systems; large-scale systems and power networks; nonlinear circuits and systems, wavelets, filter banks, and applications; neural networks; and signal processing. Content also covers the areas represented by the Society technical committees: analog signal processing, cellular neural networks and array computing, circuits and systems for communications, computer-aided network design, digital signal processing, multimedia systems and applications, neural systems and applications, nonlinear circuits and systems, power systems and power electronics and circuits, sensors and micromaching, visual signal processing and communication, and VLSI systems and applications. Lastly, the magazine covers the interests represented by the widespread conference activity of the IEEE Circuits and Systems Society. In addition to the technical articles, the magazine also covers Society administrative activities, as for instance the meetings of the Board of Governors, Society People, as for instance the stories of award winners-fellows, medalists, and so forth, and Places reached by the Society, including readable reports from the Society's conferences around the world.