Specifications

 Noise ramp and descent during bootup from power off: Fan speed noise levels ramp during the
boot process (from power off to power on) to add a layer of protection for component cooling in
case the system does not boot properly. To keep the bootup process as quiet as possible, the fan
speed reached during bootup is limited to about half of full speed.
Table 18 details the acoustical performance for the T420.
Configuration
(23 ± 2°C
ambient)
CPUs
Hard
drives
Power
supply
unit
Memory
PCI
card/HDD
controller
Operating
mode
L
WA
-UL
1
(bels)
L
pA
2
(dBA)
Prominent
tones
3
Typical
2
4 x 3.5“
SAS
(15K)
2 x
750W
6 x 4GB
1 x 10GbE
NIC
1 x PERC
H710P
Idle
4
5.1
41
Yes, by hard
drive at idle
and CPU at
stress
Stress
5
5.2
42
Feature rich
2
8 x 2.5“
SATA
(10K)
2 x
1100W
12 x
8GB
1 x 10GbE
NIC
1 x 1GbE
NIC
1 x PERC
H310
2 x 150W
GPU
Idle
4
4.7
38
Yes, by hard
drive at
stress
Stress
5
4.7
38
1
L
WA
-UL is the upper limit sound power levels (L
WA
) calculated per section 4.4.1 of ISO 9296 (1988) and measured in
accordance to ISO 7779 (2010).
2
L
pA
is the average bystander position A-weighted sound pressure level calculated per section 4.3 of ISO 9296 (1988) and
measured in accordance with ISO 7779 (2010). The system is placed within a rack enclosure (base of system is 75 cm
above floor).
3
Prominent tone: Criteria of D.6 and D.11 of ECMA-74 11th ed. (2010) are followed to determine if discrete tones are
prominent. The system is placed in center of ISO 7779 table and binaural head is at front operator position, reference ISO
7779 (2010) Section 8.6.1, position P4.
4
Idle: Reference ISO 7779 (2010) definition 3.1.7; system is running in its operating system but no other specific activity.
5
Stress: An operating mode per ISO 7779 (2010) definition 3.1.6. The software MemBW4 is activated to stress the
processors.
For more information on Dell’s acoustical design, see the Dell Enterprise Acoustics white paper.