Charles King, an analyst at Pund-IT Inc. in Hayward, Calif., believes that cluster computing, once restricted to universities and government labs, is gaining currency among businesses. "The grid idea of getting a maximum return from your IT investments, especially in the economic environment of the last couple of years, makes more and more sense," he said.

But Gordon Haff, an analyst at Nashua, N.H.-based Illuminata Inc., said that the rapidly falling prices of multiprocessor x86 servers make clusters less interesting, especially because Virtual Iron clusters would likely suffer from memory bottlenecks that would hurt their performance.

"History suggests you can mitigate long latencies, but you can't change the laws of physics," Haff said. As a result, it's questionable how broadly useful that particular capability will be. And if you take that away, Virtual Iron is a relatively late entrant to a space with a lot of players.

Brian Stevens, chief technology officer at Red Hat, which is not working with Virtual Iron, agreed. "We have seen no traction for CPU aggregation technology such as Virtual Iron's within our customer base," he said.