Shift to Express marks intro of 48-lane switch

The rollout of a 48-lane PCI Express switch has left Advanced Switching (unofficially) dead. That's the message from PLX Technology Inc. with the introduction of its new top-of-the-line product aimed at high-end servers, graphics cards and embedded systems, where Express is gaining traction. The PEX 8548 arrives as top-tier communications companies are making a transition from PCI to PCI Express, the company said.

Some of the top-tier comms and embedded OEMs were waiting for the Advanced Switching Interconnect (ASI), a variant of Express for multihost systems. But in the wake of the decision of several companies to pull the plug on ASI products, they are now migrating to Express, said Akber Kazmi, senior marketing manager at PLX.

"The major comms OEMs have no choice but to move to Express now," Kazmi said.

PLX's 48-lane chip will also be used in Advanced Telecom Computing Architecture chassis, storage arrays, servers and graphics cards supporting multiple graphics controllers and monitors. Both PLX and NEC Electronics Corp. currently ship 32-lane PCI Express switches.

The PEX 8548 sports latency of 110ns—about 40ns less than previous-generation parts—thanks to a new architecture and faster internal clock rates on the 130nm chip. An ingress port arbitration capability lets OEMs prioritize traffic for QoS by line card, channel or traffic type.

The switch also provides a programmable mechanism for handling two host CPUs for redundancy, failover or load sharing.

The PEX 8548 can handle packet payloads of up to 1,000bytes. Previous parts capped out at 256bytes.

- Rick Merritt
EE Times