IBM said the z10 doubles performance of the previous z9-class systems on some workloads. The company claims it is as powerful as 1,500 x86 servers but uses 85 percent less power and space.

Consolidating workloads on to a single system is the main rationale for today's mainframes. To make that point, last year IBM said it aims to consolidate on 33 z9 mainframes jobs now running on 3,900 of its in-house PC servers. Those jobs could run on just 16 of the z10 computers, the company said.

The new mainframe will likely be IBM's first to run OpenSolaris, the open source operating system from competitor Sun Microsystems.

"We have it running internally, but there's more work to be done to clean it up and optimize its use of the underlying hardware before we are ready for an end-user beta program," said Jim Porell, chief architect of zSeries software and an IBM distinguished engineer. "We're also looking at what will be the middleware and applications for the rest of the stack," he added.

IBM uses a custom z/OS operating system on the mainframe, but is increasingly gearing the mainframe to run a variety of open-source code. IBM estimates users are running 28 percent more Linux and 47 percent more Java workloads on the zSeries in 2007 over the previous year, Porell said.

The z10 uses up to 64 four-core processors, up from a maximum of 54 CPUs running at 2 GHz each in the previous system. The chips are based on a new core design, but one that is still single threaded.

IBM's engineers evaluated but chose not to use multithreading on the z10 as well as its predecessor. However, they have developed an ability to run in tandem jobs on the zSeries and the Cell processor that IBM co-developed for the Sony Playstation.

A company in Brazil that hosts multiuser online gaming is the customer for that hybrid system. Porell said IBM is researching the possibility of creating tools to let a broad set of users run applications across its zSeries and the Cell CPU. The Cell could be used to accelerate functions such as some forms of database analysis using local procedure calls and shared memory pools.

Each z10 mainframe can be sliced up into as many as 60 logical and secure partitions. Hundreds of jobs can be hosted on each partition using IBM's virtualization tools, said Porell.