IBM Power 780 Technical Overview And Introduction page 75

The star fabric bus topology that connects the processors together in separate drawers is
contained on SMP flex cables that are routed external to the drawers. These flex cables
attach directly to the CPU cards at the front of the drawer and are routed behind the front
covers of the drawers.
The SMP and flexible service processor (FSP) cable features described in Table 2-9 are
required to connect the processors together when system configuration is made of
two-drawer, three-drawer, or four-drawer system enclosures.
Table 2-9 Required flex cables feature codes
Enclosure MMB/MMC SMP cables
Two-drawer 3711, 3712
Three-drawer 3712, 3713
Four-drawer 3712, 3713, 3714
The cables are designed to support hot-addition of system enclosure up to the maximum
scalability. When adding a new drawer, existing cables remain in place and new cables are
added. The only exception is for cable 3711 or 3715, which is replaced when growing from a
two-drawer to three-drawer configuration.
The cables are also designed to allow the concurrent maintenance of the Power 770 or Power
780 in case the IBM service representative needs to extract a system enclosure from the
rack. The design of the flexible cables allows each system enclosure to be disconnected
without any impact on the other drawers.
MMD/MHD SMP cables
3715, 3716
3716, 3717
3716, 3717, 3718
Chapter 2. Architecture and technical overview
FSP cables
3671
3671, 3672
3671, 3672, 3673
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