Silicon Graphics 1400, Maintenance And Upgrade Manual

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Voltage Regulator Modules (VRMs)
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Voltage Regulator Modules (VRMs)
Up to six voltage regulator modules provide power for processors. Every processor
requires 1.5 VRMs, so with four processors, you must use six VRMs. Table 2-1 shows this
relationship.
You must use a specific number and connector population sequence of VRMs for each
combination of processors and termination boards. Table 2-2 lists the required number
and location of VRMs for each potential processor. Figure 2-9 shows this information
graphically.
Table 2-1
VRM and Processor Power Sequence
VRM # VRM provides power for Description
1 Processor #1 Processor core power only
2 Processor #1 and #2 L2 cache power only
3 Processor #2 Processor core power only
4 Processor #3 Processor core power only
5 Processor #3 and #4 L2 cache power only
6 Processor #4 Processor core power only
Table 2-2 Processor and VRM Population Sequencing
If you have a processor in connector # You must have a VRM in connector #
1 1 and 2
1 and 2 1, 2, and 3
1, 2, and 3 1, 2, 3, 4 and 5
1, 2, 3, and 4 1, 2, 3, 4, 5, and 6