IBM said it has no plans to produce internal benchmark comparisons which will include its products because the iSeries and pSeries hardware architectures are identical, said Jim McGaughan, director of IBM eServer strategy.
If a company is interested in comparing the performance of the eServer i5/OS operating system with that of AIX, it is likely to be considering a migration, he said. In that case, IBM would help the user evaluate workload performance on both systems, McGaughan said.
The Risc-based Power5 processor is dual-core, but unlike the Power4 chip, it has simultaneous multithreading capability. That means it can run two instruction streams in real time, or up to four threads in parallel.
Server makers are in an endless game of leapfrog with chip performance, say analysts, but the Power5-based Unix and Linux servers appear to be a significant leap.
IBM is "now pulling in intellectual property from other lines of business", such as logical partitioning from its mainframe group and virtual engine technology from its Tivoli Software group, said Brad Day, an analyst at Forrester Research.
Dave Ennen, IT director at Winnebago Industries uses an IBM zSeries mainframe to run his company's most critical applications.
He does not see Unix or other servers replacing the mainframe, despite the addition of microprocessor partitioning technology to the Unix servers.
"The reason we have the mainframe is we don't ever want it to go down, and anything short of the zSeries doesn't have that kind of dependability," said Ennen.
IBM officials said a wide gap remains between the capabilities of mainframes and those of systems running Unix. For example, unlike with Linux or Unix systems, the risk of someone cracking into a mainframe system "is almost zero", said Ravi Arimilli, an IBM fellow and chief architect of the IBM Systems Group.
Unix will eventually close the gap with improved security, availability and virtualisation, said Arimilli.
But the mainframe-like processor virtualisation capability in eServer Power5 systems will help Whirlpool.
Virtualising on the processor level means that Whirlpool can reduce the number of separate network and storage-area networking cards it needs, as well as cut licensing costs on management and monitoring systems that charge on a per-CPU basis, said Robert Gamso, senior principal systems architect at the appliance maker.
The Power4 hardware required separate adapters whereas the Power5 does not. It does not always make economic sense to add cards to achieve virtualisation, Gamso said.
Patrick Thibodeau writes for Computerworld