Specifications

68 IBM Power 770 and 780 Technical Overview and Introduction
In the rear of the rack, the FSP cables require only some room in the left side of the racks
(Figure 2-19).
Figure 2-19 Rear view of rack with detail of FSP flex cables
2.6 System bus
This section provides additional information related to the internal buses.
2.6.1 I/O buses and GX++ card
Each CEC enclosure of the Power 770 and Power 780 contains one POWER7 processor
card, where as each processor card comprises either two single-chip module POWER7
processors (#4983, #4984, or #5003) or, new to the Power 780, four single-chip module
POWER7 processors (#EP24).
Within a CEC enclosure a total of four GX++ buses are available for I/O connectivity and
expansion. Two GX++ buses off one of the two sockets are routed through the midplane to
the I/O backplane and drive two POWER7 I/O chips (POWER7 IOC) on the I/O backplane.
The two remaining GX++ buses from either of the two sockets are routed to the midplane and
feed two GX++ adapter slots.
The optional GX++ 12X DDR Adapter Dual-port (#1808), which is installed in the GX++
adapter slot, enables the attachment of a 12X loop, which runs at either SDR or DDR speed
depending upon the 12X I/O drawers attached. These GX++ adapter slots are hot-pluggable
and do not share space with any of the PCIe slots.
Two Drawer Cable
Three Drawer Cable
Four Drawer Cable
Two Drawer Cable
Three Drawer Cable
Four Drawer Cable