Each processing engine can run at 600mips, making the machine 33% more powerful than the current z/990 high-end machine.
It also offers a resilience mechanism dubbed "concurrent book removal", that allows users to replace a module, or book, containing several processors, without the need to power-down or reboot.
Normally, if processors fail, the fault tolerance mechanism automatically passes the computation work to redundant processors in the same module. With the z/9, when several processors fail, an administrator can now choose to schedule replacement of the entire module, without affecting the computational workload, experts have said.
Ray Titcombe, chairman of the IBM Computer Users Association, said, "A number of large mainframe users have held back purchases waiting for this box."
But, as businesses prepare to evaluate IBM's latest high-end offering, Computer Weekly has learned of concerns about how mainframe software will be licensed. According to Isham Research analyst Phil Payne, the software workload calculation for the new box has been biased towards batch processing work. This could make it more expensive for running real-time transaction processing applications such as IBM WebSphere or Linux applications.
"Users with heavy use of online loads could be disappointed," he said.
The z/9 is due to be generally available on 16 September, when IBM is due to confirm its software licensing scheme.