Power Supply Units; Hot Spare Feature - Dell Precision 7920 Rack Owner's Manual

The Precision 7920 Rack system supports SAS, SATA.
Supported Drives
Table 39. Supported Drives - SAS and SATA
Form Type Spe
Factor ed
2.5" SATA, 6Gb
SSD
SATA 6Gb
SAS,SS 12Gb N/A
D
SAS 12Gb 10K
SAS 12Gb 15K
3.5" SATA 6Gb
Table 40. Supported Drives - NVMe PCIe SD
Description
256GB Device
512GB Device
1TB Device

Power supply units

The power supply unit (PSU) is an internal hardware component which supplies power to the components in the system.
Your system supports the following:
● Two 1600 W or 1100 W AC power supply units (PSUs)
NOTE: For more information, see the Technical specifications section.
CAUTION: If two PSUs are installed, both the PSUs must have the Extended Power Performance (EPP)
label. Mixing PSUs (even the PSUs that have the same power rating) from previous generations of Precision
workstation is not supported. This results in a PSU mismatch condition or failure to turn the system on.
NOTE: When two identical PSUs are installed, power supply redundancy (1+1 – with redundancy or 2+0 – without
redundancy) is configured in system BIOS. In redundant mode, power is supplied to the system equally from both PSUs
when Hot Spare is disabled. When Hot Spare is enabled, one of the PSUs will be put into sleep mode when system
utilization is low in order to maximize efficiency.
NOTE: If two PSUs are used, they must be of the same maximum output power.

Hot spare feature

Your system supports the hot spare feature that significantly reduces the power overhead associated with power supply unit
(PSU) redundancy.
When the hot spare feature is enabled, one of the redundant PSUs is switched to the sleep state. The active PSU supports 100
percent of the system load, thus operating at higher efficiency. The PSU in the sleep state monitors output voltage of the active
PSU. If the output voltage of the active PSU drops, the PSU in the sleep state returns to an active output state.
If having both PSUs active is more efficient than having one PSU in the sleep state, the active PSU can also activate the
sleeping PSU.
Rotational Capacities
Speed
N/A 256GB, 512GB, 480GB, 960GB
7.2K 500GB, 1TB, 2TB
400GB, 800GB
1.8TB
600GB
7.2K 1TB, 2TB, 8TB
Technology and components 115