User's Manual

Power Management 223
Server Slot Power Priority Settings
The CMC allows users to set a power priority for each of the sixteen server
slots in an enclosure. The priority settings are 1 (highest) through 9 (lowest).
These settings are assigned to slots in the chassis, and the slot's priority will be
inherited by any server inserted in that slot. The CMC uses slot priority to
preferentially budget power to the highest priority servers in the enclosure.
If server slot priority is left with a default setting, power will be equally
apportioned to all slots. Changing the slot priorities allows administrators to
prioritize which servers are given preference for power allocations. If the more
critical server modules are left at their default slot priority of 1, and the less
critical server modules are changed to lower priority value of 2 or higher, the
priority 1 server modules would be powered on first. These higher priority
servers would then get their maximum power allocation, while lower priority
servers may be not be allocated enough power to run at their maximum
performance or they may not even power on at all, depending on how low the
limit is set and the server power requirements.
If an administrator manually powers on the low priority server modules before
the higher priority ones, the low priority server modules will be the first
modules to have their power allocation lowered to the minimum throttled
value. Once the available power allocation is exhausted, the higher priority
servers may not be able to power on as the CMC will not power server
modules off to reclaim power.
Dynamic PSU Engagement
Dynamic Power Supply Engagement (DPSE) mode is disabled by default.
DPSE saves power by running the minimum PSUs needed to power the
chassis, resulting in increased utilization of online PSUs and thus increasing
their efficiency. This results in increased PSU life, reduced heat generation,
and power savings by operating power supplies at more efficient power levels.
The system runs most efficiently with as few active PSUs as possible,
therefore:
• No Redundancy mode with DPSE is highly power efficient, with only two
supplies active and four in standby mode.