Until recently, Fibre Channel's (FC) future seemed clear, if distant, with 10Gb/s connectivity coming around 2004, up from 2Gb/s today. But then QLogic--arguably one of the most important providers of FC silicon--announced that it would also develop 4Gb/s components.
To clarify, 4Gb/s FC has always been on the roadmap for the back end, i.e., between controllers and disk drives. But for FC switches and host bus adapters (HBAs), the next stop along the road has long been 10Gb/s.
What's QLogic doing? For one, 10Gb/s FC isn't backward compatible with existing fabrics. "That was a big surprise to everyone we talked to," says Frank Berry, QLogic VP of corporate marketing. Second, if the price of 10Gb/s Ethernet is any indication--Intel's 10GbE network interface card, the PRO/10GbE LR Server Adapter has a list price of $7,995--10Gb/s FC will be very costly. In contrast, QLogic expects to be able to sell 4Gb/s ports at about the same price as 2Gb/s. Lastly, because work on 4Gb/s back end components is already well underway, "we didn't really have to do anything," Berry says.
"It's a matter of economics, really," says Randy Kerns, senior partner at the Evaluator Group. "Six months ago, I would have told you, 'This won't happen,' but now it seems like it will."
QLogic will obviously support 4Gb/s in future generations of its switches, but so far, it doesn't look like market leaders Brocade and McData will follow suit.
Brocade, for one, is on the fence. "The need to accommodate 4G[b] in a switched fabric is unclear," says a Brocade spokesperson, and "is actively working to understand if a sufficient level of end user application performance can be realized from 4G[b] fabric speed."
McData's Mike Tomky, senior product marketing manager, is more direct: "We will not stop at 4Gb/s." Why not? "There's no demand for 4Gb/s--customers are barely using up the 2Gb/s ports they already have. The only burning need they have for additional bandwidth is in ISLs [inter-switch links]," which McData will fill with 10Gb/s ports.