FCIA approves 4Gbps SAN fabrics

Will switch vendors and OEMs follow?

By Dave Simpson

Last month, the Fibre Channel Industry Association (FCIA) voted in approval of using 4Gbps Fibre Channel in switched storage area network (SAN) fabrics. Previously, 4Gbps Fibre Channel was to be limited to "inside the box" (e.g. disk drive and array) implementations, and 10Gbps was assumed to be the next speed for Fibre Channel fabrics.

According to Skip Jones, FCIA chair (and QLogic's director of planning and technology), about two-thirds of the FCIA membership participated in the vote, with 60% voting in favor, 30% opposed, and 10% abstaining.

QLogic, the number-two vendor of Fibre Channel host bus adapters (HBAs), has been the most vocal proponent of 4Gbps at the fabric level. Last week, two other HBA vendors—Agilent and JNI—announced intentions to deliver 4Gbps HBAs.

However, the leading vendor of Fibre Channel HBAs—Emulex—is not necessarily committed to delivering 4Gbps HBAs. Although Emulex is developing 4Gbps ASICs for embedded implementations and target devices, development of 4Gbps HBAs will depend on OEM demand, according to Mike Smith, executive vice president of worldwide marketing at Emulex.

"If our OEMs drive us to support 4Gbps on HBAs, we'll support it," says Smith, who notes that "up until recently, none of our OEMs were thinking about 4Gbps [at the fabric level]."

Emulex's wait-and-see stance is similar to that of the major Fibre Channel switch vendors. "We're investigating the need for 4Gbps with our OEM partners," says Tony DiCenzo, director of industry marketing at Brocade, the market share leader in Fibre Channel switches, "and right now there seems to be a limited need." DiCenzo says that OEMs are primarily concerned that development of 4Gbps products not impede development of 10Gbps Fibre Channel products.

"We're now developing around 1, 2, and 10Gbps, but our architecture does not preclude 4Gbps if the market should go that way," says Ed Chapman, senior director of product management in Cisco's storage technology group. "We have a wait-and-see approach: If our customers [end users and OEMs] ask for it, we'll provide it." Chapman says that he sees little OEM demand for 4Gbps Fibre Channel now, but that that situation could change next year.

McData, the leader in director-class Fibre Channel switches, seems more committed to the 4Gbps possibility. "We will introduce 4Gbps products when the market is ready, but we are not announcing any availability dates at this point," says Bob Williamsen, director of strategic marketing at McData. "We believe that 10Gbps products will be ready and deployed before 4Gbps products...and we don't see 4Gbps hurting 10Gbps adoption because they address different needs."

Officials from major OEMs, including EMC, say that support for 4Gbps fabrics will depend on end-user demand.

According to the FCIA's Jones, the key benefits of 4Gbps Fibre Channel at the SAN fabric level are

Twice the speed of 2Gbps Fibre Channel at about the same, or slightly higher, prices. (In contrast, 10Gbps Fibre Channel products are expected to cost 3x to 5x as much as 2Gbps Fibre Channel products.)

Full backward-compatibility with 1Gbps and 2Gbps Fibre Channel products. (In contrast, 10Gbps Fibre Channel will not be compatible with lower-speed products.)

Jones predicts that 4Gbps disk drives and HBAs will be available in sample quantities to OEMs by year-end, with production shipments coming around the middle of 2004. He believes that 10Gbps Fibre Channel products will be available in approximately the same time frame.

But even Jones says that OEMs and end users will determine the need for 4Gbps Fibre Channel. "OEMs will have to decide if they want to go to 4Gbps, and users will have a lot of say in it, too."

Some storage analysts are doubtful that 4Gbps Fibre Channel will gain momentum. "I think most vendors would want to skip 4Gbps and go straight to 10Gbps. No one wants quick churns of product lines, and vendors only do that when there's pressure from their end users or competitors," says Arun Taneja, president of the Taneja Group consulting firm (www.tanejagroup.com). "With Ethernet going straight to 10Gbps, and InfiniBand already at 10Gig and capable of 30Gig, Fibre Channel's already under pressure to leap to the higher speed."

This article was originally published on July 01, 2003