EqualLogic introduced the PS3900XV, the third model in the PS3000 line that debuted in September 2006.

The product is a Serial Attached SCSI (SAS) array and is designed to store data from high-demand applications such as Oracle Corp. or Microsoft Corp. SQL databases or Microsoft Exchange messaging and collaboration platform. SCSI stands for small computer system interface, an industry protocol for transferring data between two or more computers. The term iSCSI refers to the protocol as it is used on IP networks.

Like the previous PS3800VX the 3900 operates at up to 15,000 rpm but features larger storage capacity, 4.8TB, versus 2.3TB for the 3800.

EqualLogic iSCSI storage array can support more end users while using fewer disks, compared to orders based on the Fibre Channel (FC) protocol for transferring data, which is faster and has higher capacity than iSCSI, said John Joseph, vice president of marketing for EqualLogic.

"There is a lot of concern in the industry about 1GB [SCSI] Ethernet and how it competes against 4GB FC. Well, the wire is not the bottleneck," said Joseph.

EqualLogic says it moves data much faster across its storage arrays by automatically balancing the load between storage devices.

"We are able to load balance the workload ... without the user ever having to click on a window to reconfigure or rebalance or retune or do anything manually," he said.

Gartner forecasts that SCSI unit shipments will surpass those of FC in 2008 and continue to grow faster. Even though FC offers better performance than SCSI, SCSI is cheaper and is a more well known protocol, said Stanley Zaffos, vice president and research director for Gartner.

SCSI unit growth will be strongest in the SMB market as these companies' storage needs grow, said Zaffos.

According to 2006 research from IDC, EqualLogic holds a 19 percent market share for SCSI disks based on units shipped, second only to Network Appliance. It also competes with storage startups like LeftHand Networks and Nexsan Technologies.

The PS3900XV, which begins shipping in March, carries a list price of $67,000, although Joseph said it will be more expensive in international markets.