6947ch01.fm Draft Document for Review April 7, 2004 6:15 pm
2 IBM eServer zSeries 990 Technical Guide
The z990 servers can be configured in numerous ways to offer outstanding flexibility in
deployment of e-business on demand™ solutions. Each z990 server can operate
independently, or as part of a Parallel Sysplex cluster of servers. In addition to z/OS , the z990
can host tens to hundreds of Linux images running identical or different applications in
parallel, based on z/VM® virtualization technology.
The z990 supports a high scalable standard of performance and integration by expanding on
the balanced system approach of the IBM z/Architecture. It is designed to eliminate
bottlenecks through its virtually unlimited 64-bit addressing capability, providing plenty of
“headroom” for unpredictable growth in enterprise applications.
The z990 provides a significant increase in system scalability and opportunity for server
consolidation by providing a “multi-book” system structure that supports configurations of one
to four books. Each book consists of 12 Processor Units (PUs) and associated memory, for a
maximum of 48 processors in a four-book system. All books are interconnected with a very
high-speed internal communications links via the L2 cache, which allows the system to be
operated and controlled by the PR/SM™ facility as a symmetrical, memory-coherent
multiprocessor. The logical partitioning facility provides the ability to configure and operate as
many as 30 logical partitions, which have processors, memory, and I/O resources assigned
from any of the installed books.
The chart in Figure 1-1 shows growth improvements along all axes. While some of the
previous generation of servers have grown more along one axis for a given family, later
families focus on the other axes. Now, with the z990, the balanced design achieves
improvement equally along all 4 axes.
Figure 1-1 Balanced system design
External I/O or STI bandwidth only (Internal Coupling Channels and HiperSockets not included)
zSeries MCM internal bandwidth is 500 GB/sec. Memory bandwidth not included (not a system constraint) .
0.83ns
96 GB/sec
256 GB
32-way
1.3ns
24 GB/sec
16-way
64GB
zSeries z900
Generation 6
Generation 5
Generation 4
zSeries z9XX
System I/O Bandwidth
CPUs
Cycle
Time
Memory