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37 PowerEdge 14th generation (14G) acoustical performance and dependencies | Document ID | version (optional)
Acoustical performance of R940 in 35°C environment
Minimum Configuration
CPU TDP Load
Sound Power Level
LwA-UL
3
6.5 bels
A-weighted Sound Pressure Level
LpA
4
47 dBA
Prominent Tones, per ECMA-74
No Tones
Typical Configuration
Sound Power Level
LwA-UL
8.6 bels
A-weighted Sound Pressure Level
LpA
70 dBA
Prominent Tones, per ECMA-74
Tones Present
Feature Rich Configuration
Sound Power Level
LwA-UL
9.1 bels
A-weighted Sound Pressure Level
LpA
73 dBA
Prominent Tones, per ECMA-74
Tones Present
Footnotes:
Idle values are recorded when server is powered on with only the operating system running
Operating values represented here are the maximum observed acoustical output for either a CPU workload or an HDD workload as
prescribed in ECMA-74 12th Edition (2012).
LwA-UL is the upper limit sound power levels (LwA) calculated per section 4.4.1 of ISO 9296 (1988) with data collected in accordance with
ISO 7779 (2010) from a single sample with a total 0.3 bel production deviation applied.
LpA is the mean of A-weighted sound pressure level measured at four bystander positions per section 4.3 of ISO 9296 (1988) and measured
in accordance to ISO 7779 (2010). The system is placed in a 24U rack enclosure, 25cm above a reflective floor.
Prominent tone: Criteria of D.6 and D.11 of ECMA-74 12th ed. (2012) are followed to determine if discrete tones are prominent. The system
is placed in a 24U rack enclosure and the acoustic transducers are at front & rear bystander positions.
PowerEdge R940 acoustical dependencies
 Ambient Temperature. For a similar workload fan speeds (and thus, acoustical noise) may increase
as ambient temperature increases.
 High Wattage CPU. High-power (TDP) CPU cards may result in higher acoustical noise output.
 USB 3.0 Keys in Front USB Ports. USB 3.0 keys installed in front USB ports can induce heating of
the ambient airflow sensor and may increase fan speeds in configurations that include airflow-
controlled (i.e. not temperature controlled) PCI or NDC cards.
 NVDIMM. Fan speeds may increase under certain workloads and configurations with NVDIMMs
present.
 PCIe SSD Extender Cards. PCIe SSD Extender cards require airflow-controlled cooling;
configurations that include PCIe SSD extender cards may exhibit increased idle fan speeds (hence,
idle acoustical noise) vs. configurations without airflow-controlled cooling devices installed.
 System Thermal Profile Selected in BIOS. The default setting is “Power Optimized (DAPC)”, which
generally means lower fan speed and acoustics. If “Performance Optimized” is selected, fan speed
and acoustical noise may increase.