Designers who are trying to decide which interconnect they should use in their embedded systems should check out "System Interconnect Fabrics: Ethernet Versus RapidIO Technology." Written by Greg Shippen, this white paper provides a detailed and advanced marketing-oriented description of the logical, transport, and physical layers of these technologies.
White papers are a dime a dozen these days, and many are pretty shallow. At 56 pages, though, this one is a real treatise on the technology. Its chapters include "Interconnects Everywhere," "SystemLevel Fabric Requirements," "Ethernet Technical Overview," "RapidIO Technical Overview," "Ethernet and RapidIO Comparison," and "Practical Considerations."
RapidIO appears to offer several advantages over 1G and 10G Ethernet, including lower CPU overhead, higher bandwidth, superior quality of service, superior latency and latency jitter, lower costs (in some cases), and a growing ecosystem. But the paper offers up a great overview of both protocols, so you can make your own decision.
Shippen is a system architect with Freescale Semiconductor's Digital Systems Division. He also is part of the Technical Working Group of the RapidIO Trade Association as well as a member of the association's steering committee. The paper is published by the RapidIO Trade Association. To get your copy, go to the organization's Web site.
RapidIO Trade Association