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 in Beaverton, Oregon. "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."

Among the other IBM Unix news Tuesday:

-- A new technology for ensuring high availability for applications, called hot node and repair, will be available later in the quarter for the Power 570 and 595 systems. If a server indicates it is about to fail, the software allows an administrator to shift a workload to a different server while the first server is repaired, and then move back again without losing transactions, according to IBM.

-- IBM doubled the processor cores available in its System i servers, which run its i OS, to bring them on par with its AIX and Linux offerings. The System i 550, for example, now comes with up to eight processor cores, up from four. IBM said the move completes an effort to offer a common hardware platform for its servers running Linux, AIX or i5/OS.