Voltage Regulator Modules (Vrms); Table 3-1 Vrm/Processor Power Sequencing; Table 3-2 Processor/Vrm Population Sequencing - Silicon Graphics 1450 Maintenance Manual

Voltage Regulator Modules (VRMs)

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5. Attach the heatsink to the processor with five 6-32 X 3/8 screws, and tighten to 8-10
inch-pounds.
Follow the instructions in this section to remove and install a VRM.
Up to seven VRMs provide power for processors. Table 3-1 shows the relationship
between VRMs and processors.
Table 3-1 VRM/Processor Power Sequencing
VRM # VRM provides power for
1 (Embedded) Processor #1
2 (Embedded) Processor #1
3 (Embedded) Processor #1 and #2
4 (Embedded) Processor #3 and #4
#2 Connector Processor #2
#3 Connector Processor #3
#4 Connector Processor #4
VRMs 1 through 4 are embedded in the baseboard. Additional VRMs plug into
connectors 2 though 4 on the baseboard. You must use a specific number and connector
population sequence of VRMs for each combination of processors and termination
boards. Table 3-2 lists the required number and location of VRMs for each potential
processor.
Table 3-2 Processor/VRM Population Sequencing
If you have a processor in connector
1
1 and 2
Voltage Regulator Modules (VRMs)
Description
Processor core power only
GLT (FSB reference)
L2 cache power only
L2 cache power only
Processor core power only
Processor core power only
Processor core power only
VRM in connector #
None. All required VRMs are embedded in the baseboard.
2
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