Redundant Power Operation; Voltage Regulation; Improved Thermal Sensors And Fan Control; Phase Shedding - HP ProLiant DL160se - G6 Server Introduction Manual

By introducing these different wattage power supplies, HP gives users the option to choose a power
supply that meets, but does not exceed, their needs. Oversized and lightly loaded power supplies do
not run as efficiently as those that are heavily loaded.
Not all ProLiant 100-series G6 servers have Common Slot power supply compatibility, and not all
servers will support all available power supply wattages. Users can consult the server QuickSpecs or
server documentation for supported power supply options. The HP Power Advisor is available at the
following link to help users define the right power supply for their needs:
www.hp.com/go/hppoweradvisor.

Redundant power operation

In supported ProLiant 100-series G6 servers, redundant power supplies operate in "Balanced" mode,
where power is drawn equally from both power supplies. This mode ensures full redundancy but can
result in higher power consumption when power supplies are operating with reduced loads and lower
power efficiency.

Voltage regulation

Voltage regulators convert the 12V DC supplied from the server power supply into a variety of lower
voltages used by the different system components. HP has developed higher peak efficiency voltage
regulators that maintain greater than 90% efficiency over a broad range of power requirements. The
net result is about an 8% gain in DC power efficiency, which results in almost a 10% efficiency gain
in AC input power.
These efficiency gains come with no loss in performance and require no configuration by the user.

Improved thermal sensors and fan control

HP has added additional thermal sensors throughout the ProLiant 100-series G6 servers. The 100-
series G6 servers have "zoned" fans that increase cooling and energy efficiencies in the server by
adjusting cooling to those zones when called for by the sensors in that zone. Fan curve mapping
firmware uses temperatures reported by the sensors to control cooling fans in each zone. Fan speed is
based on the highest temperature readings reported by any of the sensors in a given fan zone.

Phase shedding

HP incorporated phase shedding into ProLiant G6 voltage regulators. Modern digital voltage
regulators deliver DC power at the proper voltage to components by using up to five different phases
of high-speed power pulses that charge capacitors. Each phase delivers its power pulses in a rotating
time window with the other phases in the voltage regulator such that the power pulses from one phase
do not overlap with those of another. The width of each pulse determines the total power delivered by
the particular phase.
Phase shedding enables the system BIOS to turn off one or more of the power phases if it determines
that the power requirements are less than the full amount of power from the voltage regulator. This
reduction in phases decreases the maximum power that the voltage regulator can deliver and
increases overall efficiency.

Memory phase shedding

Xeon 5500 Series processors support memory phase shedding. Memory phase shedding operates
much the same way as processor-based phase shedding. At power-up, the ROM BIOS determines the
number of phases needed for the memory voltage regulator based on the number of DIMMs installed.
Memory phase shedding can save up to 2.5 W per DIMM socket. This feature is less effective on
servers whose DIMM sockets are fully populated since more phases are required to accommodate
such a configuration. More phases mean more power consumption.
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