By Dave Simpson
—Products based on the next generation of Fibre Channel, which has a maximum throughput rate of 4Gbps, began trickling out early this year, and a deluge is expected in the fourth quarter. But do end users need the speed? According to an InfoStor QuickVote reader survey, about a quarter of the respondents (24%) plan to upgrade at least some of their SAN components this year, while another 19% will wait until next year to move to 4Gbps components. Yet almost half of the respondents have no plans to upgrade to 4Gbps Fibre Channel.
Generally, users in some industries (media/entertainment, for example) actually need the doubled performance, while the vast majority of Fibre Channel SAN users do not need the extra performance. However, since prices for 4Gbps Fibre Channel components are on par with those of 2Gbps components, users that need to buy new components will likely opt for the increased performance. It's important to note, however, that the overall speed of a SAN is limited to the least common denominator (e.g., the slowest components), a factor that is causing some end users to wait until more 4Gbps components are available.
A few vendors are ahead of the adoption curve for 4Gbps Fibre Channel disk subsystems and SAN components such as switches and host bus adapters (HBAs). For example, among major disk-array vendors, Engenio Information Technologies (a division of LSI) was first out the blocks in April with shipments of a 4Gbps disk array based on the company's model 6998 controller and XBB architecture. The array includes eight host ports and eight drive ports, 4GB to 16GB of cache and, compared to its predecessor, provides twice the per-port bandwidth, twice the connectivity ports, and up to 8x the cache.
Software services include replication, snapshots, remote volume mirroring, and volume copying.
Engenio officials say that early target applications for 4Gbps Fibre Channel technology include streaming video, medical imaging, data mining and data warehouses, and large high-speed OLTP databases.
The disk array has been certified with Brocade's SilkWorm 4100 SAN switch, which was the first 4Gbps Fibre Channel switch to reach production shipments. Engenio's 4Gbps array has also been certified with QLogic's 4Gbps 8/12/16-port SANbox 5602 SAN switch (which also includes four 10Gbps Fibre Channel stacking links).
Engenio's 4Gbps subsystem is resold by its OEMs, including IBM, SGI, and StorageTek (which is the process of being acquired by Sun). For example, IBM sells Engenio's 4Gbps array as the DS4800. IBM started shipping the DS4800 in June.
All of the major HBA vendors—including Emulex, LSI, and QLogic—are shipping 4Gbps Fibre Channel adapters to OEMs and other channels. End-user availability is expected in the fourth quarter.
For example, Emulex is shipping single- and dual-channel 4Gbps HBAs (LP11000 series) and I/O controllers (Helios), as well as 4Gbps embedded switches (InSpeed SOC 422).
In addition to its 4Gbps SANbox switches, QLogic is shipping 4Gbps SANblade QLE2400 series HBAs for PCI-X and PCI-Express systems.
The most recent addition to LSI's 4Gbps Fibre Channel HBA lineup is the LSI7404EP-LC, a quad-port PCI-Express adapter. LSI also sells single- and dual-port 4Gbps HBAs for both PCI-X and PCI-Express host systems.
Atto Technology was the first vendor to ship 4Gbps HBAs. For example, the company is in production shipments with its quad-channel Celerity FC-44ES adapter for PCI-Express hosts. The Celerity adapters feature Advanced Data Streaming technology for controlled acceleration of data transfers.
Last month, SANBlaze Technology announced a 4Gbps Fibre Channel version of its VirtuaLUN target emulation system (which also supports Serial Attached SCSI, or SAS). The system is available with two or four Fibre Channel ports (eight or 16 ports with the SAS version). Features include error injection, scripting, and configurable drive parameters.
For more information on 4Gbps Fibre Channel technology and products, visit the Fibre Channel Industry Association at www.fibrechannel.org