Performance Highlights Of Model 7Xx Servers - IBM 170 Servers Manual

2.4 Performance Highlights of Model 7xx Servers

7xx models were designed to accommodate a mixture of traditional "green screen" applications and more
intensive "server" environments. Interactive features may be upgraded if additional interactive capacity is
required. This is similar to disk, memory, or other features.
Each system is rated with a processor CPW which represents the relative performance (maximum
capacity) of a processor feature running a commercial processing workload (CPW) in a client/server
environment. Processor CPW is achievable when the commercial workload is not constrained by main
storage or DASD.
Each system may have one of several interactive features. Each interactive feature has an interactive
CPW associated with it. Interactive CPW represents the relative performance available to perform
host-centric (5250) workloads. The amount of interactive capacity consumed will reduce the available
processor capacity by the same amount. The following example will illustrate this performance capacity
interplay:
Model 7xx and 9/98 Model 170
CPU Distribution vs. Interactive Utilization
Model 7xx Processor FC 206B (240 / 70 CPW)
100
80
60
Available for
Client/Server
40
20
0
0 20
% of Published Interactive CPU
Applies to: Model 170 announced in 9/98 and ALL systems announced on or after 2/99
Figure 2.4. Model 7xx Utilization Example
At 110% of percent of the published interactive CPU, or 32.1% of total CPU, CFINT will use an
additional 39.8% (approximate) of the total CPU, yielding an effective interactive CPU utilization of
approximately 71.9%. This leaves approximately 28.1% of the total CPU available for client/server
work. Note that the CPU is completely utilized once the interactive workload reaches about 34%.
(CFINT would use approximately 66% CPU). At this saturation point, there is no CPU available for
client/server.
IBM i 6.1 Performance Capabilities Reference - January/April/October 2008
©
Copyright IBM Corp. 2008
Knee
40 60 80
Chapter 2 - Server Performance Behavior
Announced
Capacities
Stop Here!
available
CFINT
interactive
34%
29.2%
100 117
(7/6)
22