Overview; Design Highlights - IBM z13s Technical Manual

3.1 Overview

The z13s symmetric multiprocessor (SMP) system is the next step in an evolutionary
trajectory that began with the introduction of the IBM System/360 in 1964. Over time, the
design was adapted to the changing requirements that were dictated by the shift toward new
types of applications that clients depend on.
z13s servers offer high levels of reliability, availability, serviceability, resilience, and security. It
fits into the IBM strategy in which mainframes play a central role in creating secure
cloud-enabled, cognitive IT solutions. z13s servers are designed so that everything around
them, such as operating systems, middleware, storage, security, and network technologies
that support open standards, help you achieve your business goals.
The modular CPC drawer design aims to reduce, or in some cases even eliminate, planned
and unplanned outages. The design does so by offering advanced self-healing, concurrent
repair, replace, and upgrade functions. For more information about the z13s reliability,
availability, and serviceability (RAS) features, see Chapter 9, "Reliability, availability, and
serviceability" on page 355.
z13s servers have ultra-high frequency, large high-speed buffers (caches) and memory,
superscalar processor design, out-of-order core execution, simultaneous multithreading
(SMT), single instruction multiple data (SIMD), and flexible configuration options. It is the next
implementation of z Systems to address the ever-changing IT environment.
The CPC drawer packaging is derived from the z13. The PU single chip modules (SCMs) are
air cooled (rather than water cooled like the z13) because of lower power and cooling
requirements for the z13s SCMs.
z13s servers have several microprocessor improvements over zBC12 servers:
Higher instruction execution parallelism (improved out-or-order (OOO) instruction
handling)
Two vector execution units (SIMD)
SMT architecture that supports concurrent execution of two threads
Eight-core processor chip (6 or 7 cores per SCM enabled)
A robust cache hierarchy

3.2 Design highlights

The physical packaging of the z Systems z13s server is different from zEnterprise zBC12
(zBC12) systems. Its modular CPC drawer and SCM design address the increasing costs that
are related to building systems with ever-increasing capacities. The modular CPC drawer
design is flexible and expandable, offering unprecedented capacity to meet consolidation
needs.
z13s servers continue the line of mainframe processors that are compatible with an earlier
version. It introduces more complex instructions that are run by millicode, and more complex
instructions that are broken down into multiple operations. It uses 24-bit, 31-bit, and 64-bit
addressing modes, multiple arithmetic formats, and multiple address spaces for robust
interprocess security.
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IBM z13s Technical Guide