Specifications

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
Class
Efficiency targets by load
10%
20%
50%
100%
Redundant 51.3mm
350W AC
Platinum
82.0%
90.0%
94.0%
91.0%
550W AC
Platinum
82.0%
90.0%
94.0%
91.0%
Non-redundant
550W AC
Silver
N/A
85.0%
88.0%
85.0%
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.
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