Thermal And Acoustics; Table 17. Power Supply Efficiency; Figure 7. 550W Power Supply Unit - Dell PowerEdge R420 Technical Manual

Figure 7 shows a 550W power supply unit extended from the R420 chassis.
The PowerEdge R420 supports up to two AC PSUs with 1 + 1 redundancy, auto- sensing, and
auto- switching capability. The 350W redundant PSU (1 or 1 + 1) is recommended for a
one- processor configuration; the 350W PSU in a two- processor configuration may not provide
sufficient power, which may impact system performance.
To support the Intel turbo boost feature (default enabled in BIOS), a system with 95W processors
(8- core or 6- core) and a 550W non- redundant PSU may not sufficiently support feature rich
configurations. Using a 550W hot- plug redundant PSU for feature rich configurations is
recommended. To verify this and other possible system configurations, use the Dell Energy Smart
Solution Advisor at Dell.com/ESSA.
Dell PSUs have achieved Platinum efficiency levels as shown in Table 17.
Form factor Output
350W AC
Redundant
550W AC
Non-redundant 550W AC

Thermal and acoustics

Optimized thermal management makes the PowerEdge R420 cool and quiet. Benefiting from smart
cooling fan speed control, the R420 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 26). Operating environments for the R420 can vary from the data
center to general- use spaces. In a typical configuration, the R420 is suitable for an open office
environment.
Thermal design
The thermal design of the PowerEdge R420 reflects the following:
•
Multiple sensors are monitored for thermal feedback control: The PowerEdge R420
dynamically controls system cooling fan speed based on responses from component
28 PowerEdge R420 Technical Guide
Figure 7. 550W power supply unit
Table 17. Power supply efficiency
Class
Platinum
Platinum
Silver
Efficiency targets by load
10% 20%
82.0% 90.0%
82.0% 90.0%
N/A 85.0%
50% 100%
94.0% 91.0%
94.0% 91.0%
88.0% 85.0%