"Cost-effectively managing the growth we are experiencing requires scalability and performance [beyond] what traditional servers alone can deliver," Strasnick said.

Web and e-mail hosting provider Concentric Systems Inc. made a switch from older single-core Sparc-based servers to Sun's Niagara-based servers late last year. The company has been able to replace as many as eight of the older systems with each new server, said Barbara Branaman, Concentric's president.

"We are always looking for ways to handle more volume on fewer boxes, which of course can help us reduce energy consumption," Branaman said. "Being able to grow capacity within the same physical footprint and power envelope is a huge advantage."

To date, Concentric has deployed nine Sun Fire T2000 and T1000 Niagara-based servers. The company has plans to add five systems and is looking forward to further performance increases expected by the upcoming Niagara 2-based servers, she said.

Geoff Shorter, IT infrastructure manager at The Charlotte Observer, is expecting significant improvement in virtualization density when the newspaper begins implementing quad-core servers based on Xeon processors later this year.