New Pair of High-Performance PCIe Switches from PLX

PLX Technology, Inc. announced a new pair of high-performance PCIe switches that are ideal for control planes, back planes, gigabit Ethernet cards, host bus adapters, servers, enterprise storage, and multi-function printers. The PLX ExpressLane PEX 8617 (16 lanes, four ports) and PEX 8613 (12 lanes, three ports) are PCI-SIG PCIe 2.0 (Gen 2) specification-compliant switches with widespread applicability as an essential building block for system expansion and performance enhancement.

The PEX 8617 and PEX 8613 feature the PLX-exclusive non-transparent (NT) port functionality. An NT port isolates the address domains between two hosts which in turn enables the switches’ dual virtual channels (VCs) to provide two separate data paths for memory traffic (high and low priorities) with enhanced quality of service (QoS), regardless of CPU single VC limitations. The two VCs benefit designs by establishing dual buffer entities used to queue PCIe packets thereby improving traffic performance. The traffic class (TC) specifies priorities for a given PCIe packet and takes advantage of two VCs by sending high- or low-priority TC assignments, as opposed to the same priority for all packets found on a single VC chip.

Another PLX-only feature, integrated spread spectrum clock (SSC) isolation, provides the capability for isolating the clock domains of two systems. SSC isolation allows designers the flexibility to develop products with asynchronous clock sources, thus removing the need for a single clock source for all PCIe components in a system.

Both switches are supported by PLX’s visionPAK software design kit (SDK). This SDK is focused on getting designs to market faster and adds the ability to access internal data paths and state machines for debugging systems; a tool to measure Rx eye-width inside the device for validating signal integrity; a function to inject errors to check system behavior; loopback Tx to debug data paths, and the capability for packet performance/activity monitoring. Furthermore, fully integrated into the PEX 8617 and PEX 8613 is the unique PLX performancePAK, which provides designers additional functions to reach peak performance and includes Read Pacing to fairly allocate host port bandwidth, along with Dynamic Buffer Allocation to absorb fluctuations in bandwidth demand.

“As system requirements increase, the interconnect technology must not only keep pace in performance, but also increase in functionality,” says Jim McGregor, chief technology strategist at In-Stat. “PCI Express has become an essential element in system architectures and adding features like spread-spectrum-clock isolation and dual virtual channels adds a critical boost in performance while increasing the system flexibility for a wider range of applications.”

“Applications including dual-host/multi-host, host-failover/redundant systems and intelligent I/O modules will benefit from these new PLX switches,” said Krishna Mallampati, PLX marketing director of PCIe switch products. “Every PLX Gen 2 device incorporates NT functionality, ten of which offer two VCs, and many designers have now come to expect integrated NT for their new designs in order to avoid the additional costs and performance loss of other solutions.”

PLX’s PCIe switches provide board designers and system architects with the industry’s most extensive and proven lineup of products, ranging in density from three to 24 ports and from four to 96 lanes.
Pricing and Availability

The PEX 8617 and PEX 8613 volume prices are $18.95, and $15.35, respectively, and are sampling today with full production in June 2009.