IBM 7133 D40, Service Manual

Page: 68 / 306

Largest Configurations with One 7133
All 16 disk drive modules in a full 7133 can be connected in one loop. For a balanced
subsystem, however, it is recommended that two groups of eight disk drive modules be
connected in two separate loops, each of which is connected to a separate pair of
connectors on the SSA attachment (see Figure 29).
No improvement in performance is gained if the disk drive modules are connected in
more than two loops by way of an additional SSA attachment.
The cables are described in “SSA Cables for 7133 Models D40 and T40” on page 56.
The internal connections of the 7133 are shown in “Internal Connections (Model D40)”
on page 28 and “Internal Connections (Model T40)” on page 30.
For information about the rules for SSA loops, see the “Rules for SSA Loops” on
page 47.
1
2 2 2
2
7133 unit
4
8
1
12
4 3 2 1
Using system
A1 A2 B1 B2
5 6 7 8
9 10 11 12 13 14 15 16
13
5
9
16
Figure 29. Largest Configuration with One 7133
50
7133 Models D40 and T40 Service Guide