These are some of the z systems you may come across either in a data center or referenced in your research. You'll notice that for each flagship model, there is another system which is in the same evolutionary step as the bigger model, but these smaller resource footprint. This is intended for smaller businesses. That's been the pattern for a while now. But even on these smaller systems, you can see the progression in terms of available memory and number of processor cores, and generally speaking, new features require a specific n-level hardware like z13, 14, 15, for example. One of the important things to notice here is that in the z family, processor frequency may decrease or stay relatively flat while the amount of memory and number of configurable cores grows. For this reason, the number of MIPS, which is a unit used to measure the total amount of actual business work a machine can perform, continues to increase, and that's the important thing. A z-system can be configured with a number of varied processing units, and each processing unit is meant to accelerate a specific type of work. For example, the CP, or central processor, is something that can be used for the operating the system and it can handle just about anything that happens with software, middleware, and applications. A System Assist Processor, S-A-P, SAP, powers the channel subsystem with the CSS. An Internal Coupling Facility, or ICF, is used to run the IBM coupling facility control code for parallel Sysplex environments. IFL's Integrated Facilities for Linux is a processor unit used to run Linux or z/VM for Linux images. The zIIP, z-I-I-P, Integrated Information Processor lets these central processors offload Db2 and other eligible data workloads. HyperSockets code, global mirroring, and other newer features take advantage of these zIIP processors which offload work from the general purpose processors, potentially lowering latency and cost. Introduced on the z890 and z990 systems, the z System Application Assist Processor, zAAP is used specifically for offloading work associated with a Java based workloads. Starting with the z13, the functionality of these zAAP processors has been merged into the zIIP processor unit. If you're wondering what happened with the zAAP processors, all that has been rolled into the zIIP processors. Systems z manages processors through the LPAR assignment and weights. Those weights are assigned to a given processor pool within an LPAR. Processor Unit management with a separate processor pools simplifies capacity planning. The CPs are grouped into one processor pool, and each specialty processor unit is grouped into its own processor pool. This includes zIIPs, IFLs, and ICFs. Only Coupling Facility Control Code runs on ICF processors. Only Linux or zVM runs on IFL's. Only certain types of workloads run on zIIPs. These are intended to allow for more specialized type of work to be done without affecting licensing charges. Starting with these, z14, systems can take advantage of simultaneous multithreading technology, or SMT. This allows for two active instruction streams per core with each dynamically sharing the core's execution resources. This drastically speeds up performance, and this extends to zIIP processors for your Linux images. Here's a list of some of the functionality which can be offloaded to zIIP processor units, including aspects of XML parsing, remote mirror, HiperSockets, Db2 sort and select RMF processing. This is a chart built to show you the balanced growth in various directions and you often see it when a new system comes out. It depicts the number of processors, the amount of memory, IO bandwidth, and internal throughput rate. This is really important to understand that performance is not just about clock cycle, that growth happens in multiple dimensions, and is often dictated by current real-world demands. For specs on the latest z system, just go to ibm.com/z. It's all there. You'll also find information on all the latest features and advancements built around the capabilities of that system.
