Enterprise Server Key Product Criteria

ENERGY STAR certified servers use: more efficient power supplies with higher power factors, advanced power management features, real-time performance measurement, and lower idle draws. These requirements are summarized below. For more detailed information, please see the specification (PDF, 219 KB).

Power Supplies. Tables 1 and 2 show the efficiency and power factor requirements for server power supplies.

Table 1: Power Supply Efficiency Requirements
PSU Type Rated Output Power 10% Load 20% Load 50% Load 100% Load
Multi-Output (AC-DC & DC-DC) All Output Levels N/A 85% 88% 85%
Single-Output (AC-DC & DC-DC) All Output Levels 80% 88% 92% 88%
Table 2: Power Supply Power Factor Requirements
PSU Type Rated Output Power 10% Load 20% Load 50% Load 100% Load
Multi-output (AC-DC) All Output Levels N/A 0.80 0.90 0.95
Single-output (AC-DC) Output Rating <= 500 W N/A 0.80 0.90 0.95
500 W < Output Rating <= 1,000 W 0.65 0.80 0.90 0.95
Output Rating > 1,000 W 0.80 0.90 0.90 0.95

Power Management. Two types of power management are required to qualify for ENERGY STAR:

  • Processors must be able to reduce power consumption through dynamic voltage and frequency scaling in times of low utilization or through reduced power states in unused processor or cores.
  • Pre-installed supervisor systems (e.g., operating system, hypervisor) must have power management enabled by default.

Performance Data Measurement. Readings of input power consumption (W), inlet air temperature (°C), and average utilization, at specific minimum accuracy and frequencies, must be made available. Additionally, blade and multi-node systems must enable by default real-time inlet temperature monitoring and fan speed management.

Efficiency Criteria. Tables 3 through 5 summarize the efficiency criteria based on server type.

Table 3: Idle State Power Efficiency Requirements
Server Form Factor Number of Sockets Active Idle State Power Efficiency Requirement
Blade 1, 2, 3, 4 Information must be submitted on Server Efficiency Rating Tool (SERT) Measure and report idle state power per blade in a half-populated chassis
Multi-Node 1, 2, 3, 4 Measure and report idle state power per node in a fully-populated chassis
Pedestal or Rack Mounted 1,2 Meet idle power base allowances (with adders) as shown in Table 4 and 5
Pedestal or Rack Mounted 3, 4 Measure and report idle state power.
Table 4: Base Idle State Power Allowances for 1S and 2S Rack-Mounted or Pedestal Servers
Server Category # Installed Processors Managed Serve Base Idle Power State Allowance (Watts)
A 1 No 47
B 1 Yes 57
C 2 No 92
D 2 Yes 142
Resilient 2 Yes 205
Table 5: Additional Idle Power Allowances for 1S and 2S Rack-Mounted or Pedestal Servers
Server Category Applies to # Installed Processors
Additional Power Supplies Power supplies installed explicitly for power redundancy 20 watts per additional power supply
Hard Drives (including solid state drives) Per installed hard drive 8 watts per hard drive
Additional Memory Installed memory greater than 4 GB 0.75 watts per GB per memory
Additional Buffered DDR Channel Installed Buffered DDR Channels greater than 8 channels (Resilient Servers only) 4 watts per buffered DDR Channel
Additional I/O Devices Installed Devices greater than two ports of >=1 Gbit, onboard Ethernet < 1Gbit: No Allowance
= 1 Gbit: 2.0 watts / Active Port
> 1 Gbit and < 10 Gbit: 4.0 watts / Active Port
>= 10 Gbit: 8.0 watts / Active Port