MicroNet has launched a 5TB external serial ATA (SATA) desktop drive array which overcomes a 2TB ATA volume limit. It transfers data twice as fast as USB or FireWire-connected products and comes with built-in RAID protection and needs no operating system drivers.

The Platinum RAID Pro can have up to 5 SATA drives and utilises the external SATA (eSATA) connection method which has a data cable up to 2m long and a separate power cable for the desktop enclosure. The eSATA connection method was defined because high-capacity SATA drives, capable of transferring data at 150MB/sec in first generation SATA, can swamp USB 2.0 and FireWire 400 ports. These transfer data at burst rates of 33.5 and 36.2MB/sec respectively, thus bottlenecking drive I/O. The eSATA burst rate is 111.3MB/sec.

USB and FireWire interfaces need to translate ATA drive commands to/from their native command codes and this slows down data transfer rates. The eSATA interface is a native serial ATA interface and no translation is needed.

The ATA data addressing scheme has a 2TB volume upper limit. As drive capacities have gone past 500GB a single array can readily exceed 2TB of usable capacity. Storage needs for businesses using external drives, typically small and medium enterprises, have increased steadily over recent years with the rise of e-mail usage, richer multimedia data in things like PowerPoint decks and storage of audio and video content.

Behzad Eshghieh, MicroNet CEO, said: "Because of the growing storage demands present in the SMB space, more customers are seeking greater capacity at affordable price points. Specifically, organizations with storage-intensive digital media applications with a need for ready-to-use solutions to protect, transport and secure their irreplaceable files."

A Platinum RAID Pro with five 3Gbit/s 1TB drives and 5TB of usable capacity can now be fully used by its host server because the 2TB volume limit has been avoided through O/S developments and new features in the product's eSATA host bus adapter (HBA) and RAID controller. However, the host server must be running newer operating system versions: Windows Server 2003 and above, Windows Vista, recent Linux releases, and Mac OS X, that are not burdened with older ATA address limitations.

RAID levels run from 0, through 1, 3, 5 and 0+1 and make the product suitable as a disk-to-disk backup target. Alternatively the five disks can be treated as a JBOD.

MicroNet's Platinum RAID Pro pricing starts at $2,349 for a 2.5 terabyte array, $2,999 (c£1600 at ordinary conversion rates) for a 3.75 TB configuration and $4,499 (£2,100) for the high-end 5TB model. Customers can configure the array with appropriate eSATA HBA based on their host system requirements, either a two-port PCI-E HBA or a four-port PCI-X adapter.

Stebis and Computerworks distribute Micronet products in Europe.