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August 18, 2006

Fulcrum Targets ‘Datacenter Ethernet’ with New Switch

by Michael Feldman

Fulcrum Microsystems has introduced its latest 10 Gigabit Ethernet switch silicon, the FM4000 series IP router chips. The company is positioning the new devices as the foundation of “Datacenter Ethernet,” that is, Ethernet for high-performance computing, server and storage host interconnect, and datacenter aggregation. The FM4000 represents a superset of the FM2000 series, the company’s first low-latency 10 GbE switch chip.

Like its FM2000 predecessor, the FM4000 supports up to 24 ports and a sub-microsecond chip latency, enabling fat-tree scalability to thousands of nodes. On top of the FM2000 capabilities, the FM4000 adds layer 3 IP routing, layer 4 TCP and UDP support, and converged enhanced Ethernet (CEE) capabilities. The integrated design means chip latency for the FM4000 is an impressive 300ns, just 100ns more than the 200ns for the non-routing FM2000. While current InfiniBand chip latencies are slightly less, at 140ns, Fulcrum has managed to get its silicon into the same ballpark.

So far, 10 GbE switching has been a no-show in the datacenter, but the folks at Fulcrum sees a big opportunity there. The holy grail of converged Ethernet in the datacenter would eliminate the current islands of computing that currently exist — Fibre Channel for storage, Ethernet for the communication network between the datacenter tiers, and InfiniBand for HPC clusters.

The CEE capabilities promise to make Ethernet a more general-purpose solution for the datacenter. They provide the ability to pause communication traffic on a priority basis, which enables a lossless fabric implementation. Although CEE is not yet an Ethernet standard, Fulcrum wanted to provide some of these capabilities to give switch vendors the ability to push up against Fibre Channel and InfiniBand.

“There have been a lot of proprietary fabrics in the world, and those are all essentially dying out,” said Mike Zeile, Fulcrum Microsystems vice president of marketing. “The last one standing is InfiniBand. It’s our view that InfiniBand has worked out — in the TOP500 at least — in the absence of 10 Gig Ethernet. Once 10 Gig Ethernet becomes cost effective, along with low latency and improved scalability, then Ethernet wins.”

Current implementations of 10 GbE switches using the FM2000 technology include the Quadrics QSTenG, the Force10 S2410 and the Woven EFX 1000. As yet, none of these has proved to be the “InfiniBand killer,” although all have approached at least SDR IB switches in bandwidth and latency performance. The problem for Ethernet switch vendors is that InfiniBand is a moving target. The 10 GbE switches have just caught up with SDR, while InfiniBand vendors are already well into DDR (20 Gbps) deployment, with QDR (40 Gbps) coming next year. The additional features of the FM4000 chips, especially IP routing and CEE, may help to create some differentiation from InfiniBand solutions, but that remains to be seen.

We may not have to wait too long though. Coinciding with the Fulcrum announcement, startup Arastra is introducing its new 10 GbE switch based using the FM4000 silicon. The company has been in stealth mode while working in parallel with the Fulcrum team. Arastra is backed by a number of Silicon Valley veterans, including Sun Microsystems co-founder Andy Bechtolsheim.

Arastra’s 7100 series 10 GbE switch is a high-density, 48-port top-of-rack switch that fits into a 1U box and can scale to thousands of ports. It uses the FM4000′s CEE intelligence to manage congestion, prioritizing Ethernet traffic on a per port basis. The model enables much finer control of congestion management by slowing down the traffic at the source of the blockage.

“We envision that from the end of next year through 2009, most datacenter customers will be upgrading from 1 Gig to 10 Gig,” said Mansour Karam, director of marketing for Arastra. “Our solution will enable this upgrade by offering dense, cost effective 10 Gig switching.”

The 48-port switch can connect up to 40 servers and 8 uplinks. Early trials are ongoing with a number of government labs and Wall Street customers.