IBM spruced up its Unix servers on Tuesday with faster processors and new management software, targeting customers who want to use its hardware for virtualization and server consolidation.

The Power 570, IBM's top-selling midrange server, is now available with a 5GHz Power6 processor, which was previously available only in IBM's high-end Power 595 system. The manufacturing yields for the 5GHz chip have been good enough that IBM can offer it in higher-volume systems, said Scott Handy, IBM vice president of worldwide marketing and strategy.

IBM also doubled the maximum density for the Power 570, so customers can put up to eight 4.2GHz processors in each server node, or up to four 5GHz processors. The nodes can be stacked four high for a total of 32 4.2GHz processors in a single box.

The enhancements boost the performance customers can get from each square foot of server space and from each watt of power, making the 570 well-suited for virtualization and consolidation, Handy said.

IBM is also testing a new capability for its PowerVM virtualization software that allows administrators to share virtual system memory between partitions, in the same way they can share virtual processors today. Called Active Memory Sharing, the technology is in closed beta and due for general availability in the first half of next year.

Also planned is a new version of Active Energy Manager that lets administrators cap the energy being used by a pool of servers. Due later this quarter, the software will throttle down processor and fan speeds if an application tries to exceed a certain power threshold. The software will be a plug-in for IBM Systems Director. The portion for monitoring power use is free, but the tool for throttling down consumption will cost about US$275 per server for the Power 570, an IBM spokesman said.

IBM hopes the improvements will help keep it on top of the Unix server market. IBM regained its lead in Unix server revenue in the second quarter, growing its share 5 percentage points from a year earlier, according to IDC. Sun Microsystems, in second place, dropped 5.6 percent percentage points over the same period, while third-place Hewlett-Packard gained 1 point, IDC said.

"Ever since their resurgence in the Unix market, IBM has been pushing performance up and prices down when they really don't have to," said Dan Olds, principal analyst at Gabriel Consulting Group. "Right now they have the performance lead, and they are still pushing the speeds and feeds higher. They're keeping constant pressure on Sun and HP."