Unisys Corp."s decision this week to add a processing capacity-on-demand capability to its enterprise-class ES7000 servers is getting mixed reviews from users, who say it makes sense only for companies that expect their processing needs to grow.

Denis Baker, CIO at Sarasota Memorial Hospital in Florida, said he doesn"t need to have extra processing power on hand for the 24- and 12-processor ES7000 systems he runs. "It"s not like we"re hosting Web sites and have unknown demand that"s going to hit," Baker said. "Our user load is more static than that."

Blue Bell, Pa.-based Unisys on Wednesday announced a series of ES7000 Real-Time Capacity (RTC) models that include four inactive Intel Corp. processors along with four, eight or 12 active ones (see story). Unisys will charge a 10 percent premium upfront for the extra CPUs. But if a user eventually turns them on, the final cost will be no different than if they were initially purchased as active processors, said Mark Feverston, director of platforms for systems and technology at Unisys .

The move gives the Intel-based systems a feature already available on the company"s mainframes and on hardware offered by some of its rivals.

George Gray, an executive staff analyst at the Georgia Technology Authority in Atlanta, said the state IT agency uses the existing capacity-on-demand offering on two Unisys OS 2200 mainframes. For instance, a system that supports law enforcement activities contains eight processors, but only two of them are running, Gray said.

The IT agency is now moving more toward Windows systems and plans to purchase ES7000 machines, potentially in capacity-on-demand mode. "We"re very familiar with the concept," Gray said. "That"s why it has a great deal of surface attractiveness."

Carolyn Lightfoot, CIO at Lee College in Baytown, Texas, has two ES7000 servers and processing needs that she expects to grow over time. Lightfoot said she may consider RTC on future purchases because of the potential advantage of getting approval for present and future expenditures at one time and avoiding budget battles down the road.

But Helmut Porcher, director of operations and system software at St. Paul, Minn.-based Technology Information Education Services (TIES), said he"s inclined to buy additional processors as needed. TIES, a nonprofit consortium that provides IT services to Minnesota schools, runs four ES7000 systems, including three with 32 Xeon processors each.

Porcher noted, however, that a downside to buying processors as needed is the short duration of processor life cycles. If users wait eight to 12 months to add more processors, "you might not be able to buy additional processors that match what"s already inside your server."

That could be a problem for users who don"t want to partition their ES7000s, he said.