PMC Dips 4-Gig FC Chips

PMC-Sierra Inc. (Nasdaq: PMCS) has become the first silicon provider to announce availability of 4-Gbit/s Fibre Channel chips -- but it's not clear yet whether the technology will make its way into SAN fabrics (see PMC-Sierra Debuts 4-Gig FC Chips).

There are two different markets PMC-Sierra is targeting for its 4-Gig chips: for internal connectivity inside storage arrays to connect to 4-Gbit/s Fibre Channel drives; and for external SAN connectivity among servers, switches, and storage arrays. Of these two areas, the intra-array play is more or less a sure bet, while 4-Gig FC as a SAN interconnect is less certain (see 4-Gig Fireworks, FC Fires Up 4-Gig Fiesta, and Fibre Channel SANs: 4G or Not 4G?).

"Customers in both segments are eager to have their products ready for 4 Gig, but until now they haven't had devices to do that with," says Mark Stibitz, VP and general manager of the company's enterprise storage division.

PMC-Sierra claims it's the first to deliver 4-Gbit/s FC chips, which are pin-compatible with the 2-Gbit/s FC products it introduced in April (see PMC Goes Loopy). Stibitz says the company was able to leverage the physical layer technology from the 2-Gig design. "They are the same devices running at 4-Gig," he says.

The company's 4-port PM8377 and 18-port PM8369 PBC port bypass controllers support 4.25-Gbit/s Fibre Channel disk enclosure applications. In addition, PMC-Sierra is sampling the PM8386 QuadPHY 4GFC four-channel CMOS SerDes for Fibre Channel fabric switch and host bus adapter applications.Stibitz claims that PMC-Sierra is "engaged with all the Tier 1 storage companies" and sees broad acceptance of the technology inside enclosures. Drive makers including Seagate Technology Inc. (NYSE: STX) and Hitachi Global Storage Technologies are expected to have 4-Gig FC drives widely available at end of 2003 or the beginning of 2004.

However, SAN switch vendors, Stibitz concedes, have not yet firmed up their plans. "On the switch side, the 4-Gig FC standard has just been approved for the fabric. The switch equipment makers are evaluating their strategies for 4-Gig."

PMC-Sierra's competitors in the space include Agilent Technologies Inc. (NYSE: A), QLogic Corp. (Nasdaq: QLGC), Silicon Image Inc., Vitesse Semiconductor Corp. (Nasdaq: VTSS), and Vixel Corp. (Nasdaq: VIXL). QLogic and Vixel in particular have been vocal proponents of 4-Gig FC technology (see QLogic Gets 4-Gig FC Backers).

Arun Taneja, founder of consulting firm Taneja Group, says he believes storage array vendors will start implementing 4-Gig FC connectivity because it's only incrementally more expensive than 2-Gig components.

"As the RAID system vendors start designing their 4-Gig systems, many of them, in my view, are going to start using chips like this because the cost of the chip is very low," he says.PMC-Sierra's 18-port 4-Gig FC chips will be around $65 each in quantity, whereas Vixel's 20-port 2-Gig FC chip is around $200, according to Taneja.

Taneja believes 4-Gig SANs will ultimately happen because the cost of producing a 4-Gig FC chip will be the same as producing the 2-Gig FC chips. However, he adds, it may cause Fibre Channel vendors to become distracted on the way to 10-Gbit/s FC.

"Normally these kinds of intermediate moves are good, but the problem is that Ethernet and iSCSI are going to go directly from 1 to 10 [Gbit/s]," he says. "If there was no competition between Fibre Channel and GigE, it wouldn't be as much of an issue."

Todd Spangler, US Editor, Byte and Switch