SerialExpress-a high performance workstation interconnect

As part of the IEEE P2100 working group, we produced a SerialExpress draft standard that specifies a high-performance interconnect for use with workstations. Our goal was to develop an inexpensive, efficient, robust, scalable protocol for use in system area network (SAN) applications. Within this environment, we used buslike read and write transactions to provide an efficient mechanism for transferring data and controlling information between processor and I/O nodes. Our bandwidth, distance, and latency goals mandated the concurrent transmission of small (64-byte) packets to avoid the arbitration delay constraints of a broadcast bus protocol. We also wanted our solution to scale over a wide range of technologies. This article discusses the resulting draft standard, focusing on the technical aspects. In the future, we plan to address its implementation technologies and implications. This draft defines a protocol for low-cost, technology-independent, high-bandwidth, low-latency, and distance-insensitive interconnections for system area network applications.