IBM plans to announce this week its fifth-generation pSeries (RS\/6000) servers.The company is expected to announce two-processor to 16-processor servers called p5 (codenamed Squadron) because they are based on the Power5 processor. The Power5 processor is also used in its i5 570 (AS\/400) servers.\u00a0This introduction of RS\/6000 servers will mark the convergence of the RS\/6000 and AS\/400 servers. Both will use identical hardware, but be differentiated from the other in the type of operating system they can use.The p5 570 will be able to run AIX, i5\/OS and Linux. The i5 will come bundled with i5\/OS and will be able to also run Linux."If you are interested in the i5, it\u2019s typically because of the i5\/OS,\u201d says Nathan Brookwood, principal for Insight64 in Saratoga, Calif. \u201cWith the p5 you can buy the i5\/OS as an unbundled product, as well as Linux and AIX. It\u2019s very flexible.\u201dThe systems share other components. Each runs the IBM Virtualization Engine, which provides virtual I\/O, virtual Ethernet, dynamic LPARs (logical partitioning) and capacity on demand. The Virtualization Engine and micro-partitioning features let users create as many as 10 partitions per processor. Formerly p5 servers were only able to be partitioned by processor. For instance, if a server had four processors, only a maximum of four partitions could exist. With the new p5, users can run AIX, i5\/OS or Linux concurrently in different partitions. Capacity on demand lets users pay for only the number of processors they use.The p5 and i5 also share a technology used in IBM\u2019s mainframes called Hypervisor, which allows multiple operating systems to exist in partitions. The Power5 supports simultaneous multi-threading, which allows each CPU to process two streams of data at the same time.The new p5 servers are expected to be priced identically to the i5 servers when the i5 servers are configured without an operating system, Brookwood says.For comparison, the IBM eServer i5 520 with a 700G-byte hard drive starts at $11,360.