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Figure 6. Processor heat sink using fully ducted design (left) and a traditional heat sink in a 1U rack-mount server
(right)
Instant Thermal Monitoring provides a real-time view of heat, power, and cooling data. The Onboard
Administrator retrieves thermal information from all server blades, storage blades, and interconnect
modules in the enclosure to ensure an optimal balance between cooling, acoustic levels, and power
consumption. The Thermal Logic feature of the Onboard Administrator keeps fan and system power at
the lowest level possible. However, if the thermal load within the enclosure increases, the Thermal
Logic feature instructs the fan controllers to increase fan speeds to accommodate the additional
demand. Typically, a distributed element manager queries the thermal conditions of the hardware
every few minutes in a polling cycle. Onboard Administrator, on the other hand, monitors the thermal
conditions on the hardware in real-time, without a delay for a polling cycle.
HP’s Thermal Logic includes sophisticated algorithms in each BladeSystem ROM, iLO, and Onboard
Administrator. In combination, these algorithms minimize the power and cooling required to properly
operate the HP BladeSystem environment.
Power supplies and enclosure power subsystem
Power is delivered through a pooled power backplane that ensures that the full capacity of the power
supplies is available to all server blades. BladeSystem c3000 power supplies are single-phase power
supplies, supporting both low-line and high-line environments. Wattage output per power supply
depends on the rated alternating current (AC) input voltage. The BladeSystem c3000 Enclosure ships
with two power supplies; however, up to six power supplies can be installed, depending on the AC
redundancy level required and the number of devices installed in the enclosure. AC power supplies
auto-switch between 100VAC and 240VAC, to provide deployment options.
The BladeSystem c3000 Enclosure houses the power supplies in the same enclosure as the server
blades, storage blades, and interconnect modules (Figure 7). The power supply modules connect to a
passive power backplane that distributes power to all the components in a shared manner. Moving
the power supplies into the enclosure allowed HP to reduce the transmission distance for DC power
distribution and to use an industry-standard 12V infrastructure for the BladeSystem c-Class. Using a
12V infrastructure allowed HP to eliminate several power-related components and improve power
efficiency on the server blades and in the infrastructure. The control circuitry was stripped and put on
the management board and fans.
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