EMC Corp. Sunday will unveil its first midrange Centera content addressed storage (CAS) array, which offers the same functionality as its bigger and more expensive brother with only half the capacity -- 2.2TB.

The new Centera uses the same internal architecture as the high-end Centera system: a redundant array of independent nodes that marries one Intel processor to each tray of four disk drives.

The new rack-mountable Centera can be configured for both storage and access.

The midrange system is the first major hardware change in EMC"s CAS system line since the high-end Centera was first brought out in April 2002.

"This will allow (small and midsize businesses) to use an archiving system to finally get their data in a sustainable state, and where they"re not backing up the same data all the time," said Anne MacFarland, an analyst at The Clipper Group Inc. in Wellesley, Mass.

The new box also incorporates the Advanced Technology Attachment disk drives that the high-end model uses.

Arun Taneja, an analyst at Taneja Group Inc. in Hopkinton, Mass., said price/performance improvements in future midrange systems may one day make the high-end offering obsolete.

To guard against that, EMC"s marketing scheme doesn"t offer expandability beyond the new system"s four nodes.

"In the next two or three months, EMC will face pressure from the marketplace to make this product upgradable from four to eight nodes," Taneja said.

Like the original Centera, the new box comes with remote replication, file indexing and search capabilities, as well as several bundled software systems that can archive data to meet regulatory requirements.

Roy Sanford, vice president of CAS at EMC, said the new Centera is also available bundled with e-mail archiving software, such as EMC"s Legato DiskXtender and EmailXtender.

Sanford declined to disclose specific pricing plans but said the new model will cost about 35 percent less than the high-end one, which starts at about US$148,000. "This will be sub-$100,000," Sanford said.