Dell on Monday launched a disk array comprising 2.5-inch drives that deliver higher performance per 1U system than arrays with more commonly used 3.5-inch drives.

The PowerVault MD1120 is Dell's first storage expansion enclosure built with 2.5-inch drives. Until the recent introduction of 300-GB 2.5-inch drives, the smaller devices didn't have sufficient capacity for storage devices like the MD1120, Praveen Asthana, director of storage and networking at Dell, told InformationWeek.

"We see that as a turning point in the industry," Asthana said of the higher-capacity 2.5-inch drives.

The new product is a direct-attached storage device for small companies with a few business applications running on a server, Asthana said. The device is also good for e-mail storage, particularly since Microsoft has added DAS intelligence in Exchange 2007.

Using Dell's PowerEdge RAID controller, the MD1120 can scale up to six enclosures for a total of 144 drives. The new product delivers twice the I/O performance per 1U system as a similar device comprising 3.5-inch drives, Dell said. Enclosures using the latter drives, however, are still necessary if higher capacity is required.

The drives are connected to a 3-Gbps serial-attached SCSI, or SAS, interface, making the MD1120 an option for supporting business applications such as e-mail, databases, and online transaction processing.

The MD1120 is scheduled to be available this month. The price of an average system of 20 drives is $10,000.

Direct-attached storage is a digital system connected to a server or workstation without a storage network in between. The term is used to differentiate non-networked storage from storage area networks, or SANs, and networked-attached storage, or NAS.