Dynamic Power Saver Mode - HP Xw460c - ProLiant - Blade Workstation Overview

available in the technology brief entitled ―Managing the HP BladeSystem c-Class‖:
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http://h20000.www2.hp.com/bc/docs/support/SupportManual/c00814176/c00814176.pdf

Dynamic Power Saver mode

Most power supplies operate more efficiently when heavily loaded and less efficiently when lightly
loaded. Dynamic Power Saver mode provides power load shifting for maximum efficiency and
reliability. Dynamic Power Saver technology maximizes power supply efficiency to reduce operating
costs. Power supply efficiency is simply a measure of DC watts output divided by AC or DC watts
input. At 50% efficiency, 2000W input would yield 1000W output. The difference is costly wasted
energy that generates unnecessary heat.
Dynamic Power Saver mode is active by default since it saves power in the majority of situations.
When enabled, Dynamic Power Saver runs the required power supplies at a higher use rate and puts
unneeded power supplies in standby mode. A typical power supply running at 20% load could have
an efficiency rating as low as 60%. However, at 50% load, the efficiency rating could be up to 92%,
providing a significant savings in power consumption.
In the first example in Figure 21, without Dynamic Power Saver, power demand is low and spread
inefficiently across six power supplies. In the second example, with Dynamic Power Saver active, the
power load is shifted to two power supplies for more efficient operation. The remaining power
supplies are placed in a standby condition. When power demand increases, the standby power
supplies instantaneously deliver the required extra power. This enables the power supplies to operate
at optimum efficiency, with no effect on redundancy.
Figure 21. Example of power efficiency with and without Dynamic Power Saver
Dynamic Power Saver is enabled by the BladeSystem Onboard Administrator module. When
enabled, this feature monitors the total power consumed by the enclosure in real-time and
automatically adjusts for changes in demand.
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