ups and operations. Any unused PUs can be utilized as spares. The inactive PUs on the MCM are available to be characterized as either Central Processors (CPs), Internal Coupling Facility (ICF) processors for Coupling Facility applications, Integrated Facility Linux (IFL) for Linux appli- cations, or as IBM ^zSeries Application Assist Processor (zAAP) engines, providing enterprises with tre- mendous fl exibility in confi guring the best system for run- ning applications. Each model of the z890 must always be ordered with at least one CP, IFL or ICF.
The PU, which uses the latest chip technology from IBM semiconductor laboratories, is built on CMOS
The z890 is a single book design. The book can support up to 32 GB of memory on a single memory card and 8
The z890 supports LPAR mode only (basic mode is no longer supported).
The MultiChip Module (MCM) is the technology corner- stone for fl exible PU deployment in the z890 models. For most models, the ability of the MCM to have inactive PUs allows such features as Capacity Upgrade on Demand
(CUoD), Customer Initiated Upgrades (CIU), and the ability to add CPs, ICFs, IFLs and zAAPs dynamically provid- ing nondisruptive upgrade of processing capability. Also, the ability to add CPs lets a z890 with spare PU capacity become a backup for other systems in the enterprise; expanding the z890 system to meet an emergency outage situation. This is called Capacity BackUp (CBU).
The I/O SubSystem has been enhanced to support two Logical Channel SubSystems (LCSSs) which provide the capability to defi ne up to 512 CHPIDs (256 CHPIDs per operating system image). I/O improvements in the Parallel Sysplex Coupling Link architecture and technology sup- port faster and more effi cient transmission between the Coupling Facility and production systems. HiperSockets™ provides
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