Acoustical Design - Dell PowerEdge R620 Technical Manual

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 R620 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
BIOS setup screen. For more information, see the
Dell.com/Support/Manuals
and Power Goals" on Dell.com.

Cooling redundancy: The R620 allows continuous operation with a fan failure in the system.

Environmental specifications: The optimized thermal management makes the R620 reliable
under a wide range of operating environments as shown in the environmental specifications in
Table 33. Many configurations are also compliant under expanded operating temperature
environments, but a few are not.

Acoustical design

The acoustical design of the PowerEdge R620 reflects the following:

Versatility: The PowerEdge R620 saves you power draw in the data center, but it also is quiet
enough for the office environment in typical and minimum configurations. Compare the values
for L in Table 23 for these configurations and note that they are lower than ambient
pA
measurements of typical office environments.

Adherence to Dell's high sound quality standards: Sound quality is different from sound power
level and sound pressure level in that it describes how humans respond to annoyances in sound,
like whistles and hums. One of the sound quality metrics in the Dell specification is prominence
ratio of a tone, which is listed in Table 23.

Noise ramp and descent during bootup from power off: Fan speeds and noise levels ramp
during the boot process (from power off to power on) in order to add a layer of protection for
component cooling in the case that the system were not to boot properly. To keep bootup as
quiet as possible, the fan speed reached during bootup is limited to about half of full speed.

Noise level dependencies: If acoustics is important to you, you may want to make the following
configuration choices and settings for the PowerEdge R620 because they result in quieter
operation:
iDRAC7 BIOS settings: Performance Per Watt (DAPC or OS) may be quieter than Performance
—
or Dense Configuration (iDRAC Settings > Thermal > Max. Exhaust Temperature or Fan speed
offset).
Hot spare feature of power supply unit: In the system default setting, the Hot Spare Feature is
—
disabled; acoustical output from the power supplies is lowest in this setting.
Hard drive noise is highly dependent on spindle speed; a 7.2K RPM SATA hard drive has the
—
quietest hard drive operation and a 15K RPM SAS hard drive has the loudest.
However, some components cause significant but not necessarily intuitive increases in loudness
when they are installed in the R620. Contributors to acoustical output can include:
PCIe SSD cards (such as Fusion-io)
—
GPUs
—
Express Flash PCIe SSDs
—
10Gb NIC
—
Number of installed processors
—
Number of installed PCIe cards
—
36 PowerEdge R620 Technical Guide
and "Advanced Thermal Control: Optimizing across Environments
Dell PowerEdge R620 Owner's Manual
on