Integrated Lights-Out technology: enhancing the manageability of ProLiant servers technology brief

HP Dynamic Power Capping
Some ProLiant servers support HP Dynamic Power Capping. Dynamic Power Capping uses special
hardware in the server to bring a server experiencing a sudden increase in workload back under its
power cap in less than one-half second. This prevents any surge in power demand that could cause
an enterprise-class circuit breaker to trip. Dynamic Power Capping has been designed and tested to
ensure that it can prevent tripping circuit breakers that have a specified trip time of three seconds or
longer at 50 degrees C and at a 150 percent overload.
To implement Dynamic Power Capping, the iLO 2 management processor works in conjunction with a
power microcontroller to measure and control power consumption. When enforcing the Dynamic
Power Cap, the power microcontroller keeps the processor’s power consumption under a specified
cap (see Figure 7). Administrators can set Dynamic Power Caps for individual servers from the iLO 2
user interface when using an iLO 2 Advanced Pack license. Dynamic Power Caps for multiple rack-
mount servers can be set from the power management module within HP Insight Control Environment.
HP Dynamic Power Capping is operating-system independent and functions with all operating systems
and software applications. It will continue to function even if the OS should fail.
Figure 7. A rapid response of Dynamic Power Capping can avoid circuit breaker trips.
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