IBM's recently announced new eServer p5 servers contain an updated version of the Power series processor. It's said to offer more - of course - and to beat the opposition, especially HP, into a cocked hat. Using as few as a quarter of the number of processors, eServer p5 systems outperform HP servers, says IBM.

The advantage of the 276-million transistor, dual-core Power5, as with almost all new processors, is to allow users to save money by performing the same workload with fewer CPUs, or more with the same number of CPUs. Aimed primarily at the IBM AIX market, IBM says that its share of the $21 billion enterprise Unix market is predicted by researcher IDC to increase over the next three years. Primarily though, it could be argued that this is because market leader HP is perceived as shifting its emphasis away from its own HP/UX.

So what does the new chip offer?

According to IBM, the new Power5 processor allows vendors to build multi-way servers, using up to 16 CPUs. Product manager Adalio Sanchez believes the core benefit is virtualisation. He reckons that one 16-way P5 server can support up to 5,000 SAP users - and that's more, he claims, than one of Sun's 72-way servers. The chip manages this through micro-partitioning, splitting each CPU into up to 10 virtual machines (VMs), each of which addresses a NIC and other I/O devices. IBM reckons it has patented the technology, and sees the advantage as being the ability to re-provision servers within seconds, moving VMs with different OSes around as loads fluctuate, although this feature isn't likely to appear until the Power5+ arrives next year. The Power5 uses IBM's 0.13-micron copper wiring and SOI (Silicon-on-Insulator) technologies.

In terms of finished systems, IBM is initially offering three servers for small to medium-sized enterprises (SMEs) up to large enterprises. The deskside or rack-mount p5-520 will be a two-way, entry level system using a 1.65GHz Power5 with up to 32GB of memory. The mid-range deskside or rack-mount p5-550 will scale up to four-way and be equipped with up to 64GB of memory running the 1.65GHz processor, while the p5-570 will scale up to 16-way, with a 1.9GHz chip. All will be able to run either AIX5L or Linux. At the entry-level, IBM promises a p5-570 Express, running a 1.5GHz processor and up to 256GB of memory for SMEs.