Power Conservation and Power Budget
CMC conserves power when the user-configured maximum power limit is reached. When the demand
for power exceeds the user configured System Input Power Cap, CMC reduces power to servers in
reverse-priority order to free power for higher priority servers and other modules in the chassis.
If all or multiple slots in the chassis are configured with the same priority level, CMC decreases power to
servers in the order of increasing slot number. For example, if the servers in slots 1 and 2 have the same
priority level, the power for the server in slot 1 is decreased before that of the server in slot 2.
NOTE: You can assign a priority level to each server in the chassis assigning a number from 1
through 9 for each server. The default priority level for all servers is 1. The lower the number, the
higher the priority level.
The power budget is limited to a maximum of whichever set of two PSUs that is the weakest. If you
attempt to set an AC power budget value that exceeds the System Input Power Cap value, CMC displays
a message. The power budget is limited to 4800W.
Maximum Power Conservation Mode
This is enabled for Grid Redundancy or PSU Redundancy modes. CMC performs maximum power
conservation when:
• Maximum conservation mode is enabled.
• An automated command line script, issued by a UPS device, enables maximum conservation mode.
In maximum power conservation mode, all servers start functioning at their minimum power levels, and
all subsequent server power allocation requests are denied. In this mode, the performance of powered
on servers may be degraded. Additional servers cannot be powered on, regardless of server priority.
The system is restored to full performance when the maximum conservation mode is cleared.
Server Power Reduction to Maintain Power Budget
CMC reduces power allocations of low-priority servers, when additional power is required to maintain the
system power consumption within the user-configured System Input Power Cap. For example, when a
new server is engaged, CMC may decrease power to low-priority servers to allow more power for the
new server. If the amount of power is still insufficient after reducing power allocations of the lower
priority servers, CMC lowers the performance of servers until sufficient power is freed to power the new
server.
CMC reduces server power allocation in two cases:
• Overall power consumption exceeds the configurable System Input Power Cap.
• A power failure occurs in a non-redundant configuration.
110V PSUs AC Operation
By default, the 110V PSU AC Operation feature is available. However, a combination of 110V and 220V
operation is not supported. If CMC detects that both voltages are input, one voltage value is selected and
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