Dell PowerEdge R820 Technical Manual page 30

Figure 8 shows a 750W power supply unit extended from the R820 chassis.
The PowerEdge R820 supports up to two AC-DC or DC-DC power supplies with 1 + 1 redundancy,
auto-sensing, and auto-switching capability.
Dell PSUs have achieved Platinum efficiency levels as shown in Table 19.
Form factor Output
750W AC
Redundant 86mm 1100W AC
1100W DC
Optimized thermal management makes the PowerEdge R820 cool and quiet. Benefiting from smart
cooling fan speed control, the R820 can keep both high performance and good acoustics across a
wide range of ambient temperatures from 10°C to 35°C (50°F to 95°F) and to extended ambient
temperature ranges (see Table 29). Operating environments for the R820 can vary from the data
center to general-use spaces. In typical a configuration, the R820 is suitable for an open office
environment.
The thermal design of the PowerEdge R820 reflects the following:

Multiple sensors are monitored for thermal feedback control: The PowerEdge R820
dynamically controls system cooling fan speed based on responses from all component
temperature sensors, including processors, hard disk drives, DIMMs, storage cards, and the inlet
ambient temperature. Thermal control detects and responds to hardware configuration. Thermal
management adjusts cooling according to what the system really needs, and draws lower fan
power draw and generates lower acoustical noise levels than servers without such controls.

User-configurable settings: An R820 thermal control design target is to minimize the
contribution of fan power to overall system power. However, with the understanding and
realization that every customer has a unique set of circumstances or expectations of the system,
in this generation of servers, we are introducing limited user-configurable settings in the iDRAC7
30 PowerEdge R820 Technical Guide
Class
10%
Platinum 82.0%
Platinum 89.0%
Silver 80.0%
Efficiency targets by load
20% 50%
90.0% 94.0%
93.0% 94.5%
88.0% 91.0%
100%
91.0%
92.0%
88.0%