Thermal And Acoustics; Table 16. Power Supply Efficiency; Figure 7. 750W Power Supply Unit - Dell PowerEdge R520 Technical Manual

Figure 7 shows a 750W power supply unit extended from the R520 chassis.
Dell PSUs have achieved Titanium efficiency levels as shown in Table 16.
Form factor Output
495W AC
750W AC
750W AC
Redundant 86mm
1100W AC
1100W DC
Cabled 550W AC

Thermal and acoustics

Optimized thermal management makes the PowerEdge R520 cool and quiet. Benefiting from smart
cooling fan speed control, the R520 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 25). Operating environments for the R520 can vary from the data
center to general-use spaces. In a typical configuration, the R520 is suitable for an open office
environment.
Thermal design
The thermal design of the PowerEdge R520 reflects the following:

Multiple sensors are monitored for thermal feedback control: The PowerEdge R520
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, resulting in lower fan
power draw and lower acoustical noise levels than servers without such controls.

User-configurable settings: An R520 thermal control design target is to minimize the
contribution of fan power to overall system power. However, with the understanding and
28 PowerEdge R520 Technical Guide
Figure 7. 750W power supply unit
Table 16. Power supply efficiency
Class
Platinum
Platinum
Titanium
Platinum
N/A
Silver
Efficiency targets by load
10% 20%
82.0% 90.0%
82.0% 90.0%
90.0% 94.0%
89.0% 93.0%
80.0% 88.0%
N/A 85.0%
50% 100%
94.0% 91.0%
94.0% 91.0%
96.0% 91.0%
94.5% 92.0%
91.0% 88.0%
88.0% 85.0%