Power, Thermal, Acoustic; Power Supplies; Power Distribution Board; 2 B P Ower Efficiency - Dell PowerEdge R815 Technical Manual

Dell

4 Power, Thermal, Acoustic

4.1

Power Supplies

The power supply subsystem supports up to two AC-DC power supplies (1+1 redundant
configuration) connected indirectly to the CPU planar through a Power Distribution
Board (PDB). The power supply only provides +12V and +12Vaux. There are several
voltage regulators in the system to supply different voltage levels needed by different
logic devices.
4.2

Power Distribution Board

The Power Distribution Board (PDB) distributes power from the Power Supply Unit
(PSU) to the CPU and IO planars. The Power Management bus enables power supply
monitoring and load balancing. The CPU planar connects directly to the PDB through a
32-pin and 6-blade connector. The IO planar connects to the PDB through a 12-
conductor (2x6) cable. The standby power is routed through the CPU planar and IO
planar via Air-max connector.
4.3 P ower Efficiency
4 2 B
One of the main features of the 11G family of servers is enhanced power efficiency.
R815 achieves higher power efficiency by implementing the following features:

User-selectable power cap (subsystems will throttle to maintain the specified
power cap)

Improved power budgeting

Accurate inlet temperature

PSU/VR efficiency improvements

Switching regulators instead of linear regulators

Closed loop thermal throttling

Increased rear venting/3D venting

PWM fans with an increased number of fan zones and configuration-dependent
fan speeds

Use of DDR3 memory (lower voltage compared to DDR2, UDIMM support)

CPU VR dynamic phase shedding

Memory VR static phase shedding

Random time interval for system start (Allows an entire rack to power on
without exceeding the available power)

BIOS Power/Performance options page

Active Power Controller (BIOS-based CPU P-state manager)

Ability to power down or throttle memory
Dell PowerEdge R815 Technical Guide
20