Hitachi has separated its storage controller from the backend array of disks, said John Webster, an analyst with Data Mobility Group LLC in Nashua, N.H.

`"Why should people pay a premium for them [disks] when they don't want to?" he said. "Why don't we just separate the two and let customers buy one and match up the storage on the back the way they want to?"

The Hitachi TagmaStore Network Storage Controller model NSC55 "Disk-less" version provides the same functionality as the Hitachi TagmaStore Network Storage Controller model NSC55, announced last July, said Claus Mikkelsen, chief scientist for the Santa Clara, Calif. company.

"This is going to appeal to a broad range of customers," Webster said. "Large end-users have wanted to do exactly this for a long time. Midrange customer would like a way to acquire a virtualized storage environment just by buying the controller, because that's where the virtualization is."

The device comes in two configurations: one starts with 4GB of cache and 16 Fibre Channel ports, for $90,000, and the other starts with 64GB of cache and 48 Fibre Channel ports, for US$175,000. The devices are generally available this week.