Using PCI Express as a system interconnect enables high performance 3U VPX solutions to be constructed. With higher bandwidth and new capabilities, this new switch allows more innovative system architectures and improves application portability.
By Nigel Forrester, Concurrent Technologies | February 2016
PCI Express is a high-speed serial interface standard that was designed to provide point to point connectivity between a processor and multiple peripherals. Gen 3 PCI Express supports a transfer rate of 8GT/s, which equates to 984 MB/s per lane. One of the challenges, especially for embedded use, has been extending the PCI Express architecture of a single root complex connecting to multiple endpoints. One solution is ExpressFabric® and Concurrent Technologies has just announced FR 341/x06, a 3U VPX switch designed to enable more flexible PCI Express configurations.
FR 341/x06 supports six Gen 3 PCI Express payload boards with a default configuration of a single processor board acting as the root complex for up to five additional payload boards. In addition, two other modes of operation are supported, called virtual switch and fabric mode. The virtual switch mode allows multiple partitioned root complexes to be set up which could, for example, enable three individual clusters consisting of pairs of boards to be set up within a six slot system. The fabric mode allows multiple root complexes with links between the clusters, enabling extremely flexible configurations while still using standard PCI Express enumeration. Previously this type of PCI Express configuration required the use of additional hardware on boards to implement non-transparent bridge capability adding complexity and power consumption. The main advantage is simplification: FR 341/x06 enables standard applications to run more easily and avoids a lot of the complicated payload configuration required.
At the solution level, multiple hosts residing on PCI Express fabrics communicate through an Ethernet type of protocol, enabling socket-based application software to run without modification. There is also a special host-to-host communication capability for short packets, called Tunnelled Windows Connection. This enables high performance computer applications that are message-based to share small amounts of information with very low latency.
Caption: The new FR 341/x06 from Concurrent Technologies supports six Gen 3 PCI Express payload boards with a default configuration of a single processor board