IBM last week expanded its family of iSeries servers with the introduction of the eServer i5 550.The eServer i5 550 fits in IBM\u2019s line-up between the two-processor i5 520 and the 16-processor i5 570. All three servers use IBM\u2019s Power5 processor, which IBM shipped in May. The Power5 jams two processors onto one chip.The i5 550 has from one to four processors and features advanced virtualization techniques that let it run multiple operating systems and applications simultaneously. The i5 550 supports i5\/OS V5R3, Linux, AIX 5L, Microsoft Windows Server via Intel processor-based blades that run Windows, and WebSphere and Lotus Domino.The server is designed to consolidate workloads from other servers.It features on-demand capabilities, which let users switch on additional processing when needed. The i5 550 ships with only two of its four processors turned on. IBM charges about $3,700 to turn on additional processors.The i5 550 uses a 64-bit 1.65-GHz processor with as much as 64G bytes of main memory and 38 terabytes of disk storage. It features five PCI-X slots and two 10\/100\/1000M bit\/sec Ethernet ports. It supports hot-pluggable disk drives and redundant hot-pluggable cooling fans.The i5 550 is available either in a deskside tower or a rack-mounted configuration. It supports dynamic logical partitioning, where system resources can be grouped logically and processors can be shared among partitions. It also supports simultaneous multithreading and micro-partitioning in which less than a full processor is allocated to a logical partition.The i5 550, starting at $74,000, is expected to be available next month.