Capacity And Performance - IBM z13s Technical Manual

also includes innovative SMT capability, and provides 139 SIMD vector instruction subset for
better performance.
Depending on the model, z13s servers can support from 64 GB to a maximum of 4 TB of
usable memory, with up to 2 TB of usable memory per CPC drawer. In addition, a fixed
amount of 40 GB is reserved for the hardware system area (HSA) and is not part of
customer-purchased memory. Memory is implemented as a redundant array of independent
memory (RAIM) and uses extra physical memory as spare memory. The RAIM function uses
20% of the physical installed memory in each CPC drawer.

1.2.2 Capacity and performance

The z13s server provides increased processing and I/O capacity over its predecessor, the
zBC12 system. This capacity is achieved both by increasing the performance of the individual
processor units, which increases the number of PUs per system, redesigning the system
cache and increasing the amount of memory. The increased performance and the total
system capacity available, with possible energy savings, allow consolidating diverse
applications on a single platform, with significant financial savings. The introduction of new
technologies and instruction set ensure that the z13s server is a high performance, reliable,
and secure platform. z13s servers are designed to maximize resource exploitation and
utilization, and allows you to integrate and consolidate applications and data across your
enterprise IT infrastructure.
z13s servers come in two models: The N10 (10 configurable PUs) and N20 (20 configurable
PUs). An N20 can have one or two CPC drawers. Each drawer has two nodes (N10 only one).
Each node has 13 PUs available for characterization. The second drawer for an N20 is added
when more than 2 TB of memory or more I/O features are needed.
IBM z13s Model Capacity Identifier A01 is estimated to provide 60% more total system
capacity than the zBC12 Model capacity Identifier A01, with the same amount of memory and
power requirements. With up to 4 TB of main storage and SMT, the performance of the z13s
processors provide considerable improvement. Uniprocessor performance has also
increased significantly. A z13s Model z01 offers, on average, performance improvements of
34% over the zBC12 Model z01. However, variations on the observed performance
increasingly depend on the workload type.
The IFL and zIIP processor units on z13s servers can run two simultaneous threads per clock
cycle in a single processor, increasing the capacity of the IFL and zIIP processors up to
1.2 times and 1.25 times over the zBC12. However, the observed performance increase
varies depending on the workload type.
z13s servers offer 26 capacity levels for six processors that can be characterized as CP. This
configuration gives a total of 156 distinct capacity settings and provides a range of 80 - 7123
MIPS. z13s servers deliver scalability and granularity to meet the needs of medium-sized
enterprises, while also satisfying the requirements of large enterprises that have demanding,
mission-critical transaction and data processing requirements.
This comparison is based on the Large System Performance Reference (LSPR) mixed
workload analysis. For a description about performance and workload variation on z13s
servers, see Chapter 12, "Performance" on page 437. For more information about LSPR, see:
https://www.ibm.com/servers/resourcelink/lib03060.nsf/pages/lsprindex
z13s servers continue to offer all the specialty engines that are available on previous z
Systems except for IBM System z® Application Assist Processors (zAAPs). A zAAP qualified
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IBM z13s Technical Guide