White Paper

Dell Power Center’s Power Policies for 12
th
-Generation Servers
14
Setting priorities in dynamic policy Figure 7.
The power cap is
dynamically distributed
based on the priority
The main purpose of a dynamic policy is to maintain the group budget and to balance the power
resources to optimize the performance of the servers in the group, based on recent measurements of
power consumption. After measurement of the power consumption of all servers in the group is done,
Power Center lowers the cap on servers not using their entire power budget. This creates an excess
power budget, known as headroom, which is then applied to other servers needing more power in the
group, considering priority. After all power caps are calculated, they are sent to Node Manager to be
executed on each server. When the total power budget has been allocated and there is no further
headroom, a temporary static state is reached where no further power balancing occurs. If a server
continues to exceed its power cap, more power will not be allocated to it. Instead, an event is sent to
the administrator for appropriate mitigation. The administrator in this case might want to increase the
group capping value to allow more power budget for the group or adjust the workloads to keep the
servers working under their imposed power caps. Otherwise, keeping the server at an unachievable
cap level will impact the performance of the servers, and the power budgeting process may no longer
be effective, possibly leading to power circuit breakers being tripped if power is truly constrained.