ENERGY STAR Program Requirements for Computer Servers: Final Draft Test Method (Rev. Jan-2023), Version 4.0

Overview

This seven-page document is the test method for determining compliance with the ENERGY STAR Computer Servers specification and for obtaining idle and active state power data for certification. It does not apply to the power supply efficiency and power factor requirements in Section 3.2 of the specification; DOE revised the overview to make clear that the voltage and related power conditions do not apply to power supply testing.

Test setup begins with three input power tables. For products with nameplate power of 1,500 W or less, voltage tolerance is 1.0% and maximum total harmonic distortion is 2.0%; above 1,500 W these become 4.0% and 5.0%. Supply voltages are 230 V or 115 V ac (100 V optional for the Japanese market), and three-phase servers use 208 V (North America) or 400 V (Europe). Frequency tolerance is 1.0%. Ambient temperature must be 25 ± 5 °C and relative humidity 15% to 80%.

The power analyzer must report true RMS power, with a current crest factor of at least 3, a minimum frequency response of 3.0 kHz, 1% or better accuracy, at least one reading per second and calibration within the past year. The temperature sensor sits no more than 50 mm upwind of the main air inlet, with ± 0.5 °C accuracy and at least 4 samples per minute. Active state testing uses the most current SPEC SERT.

Units are tested as shipped, with hardware, BIOS and power management at defaults. Power is measured between the ac source and the unit, with no UPS in between. Blade systems are tested at chassis input in a half-populated chassis (full population optional); multi-node systems are tested in a fully populated chassis, and idle power is divided by the node count. Result files such as Results.xml and Results.txt accompany the report.

Key points

1. Ambient temperature during testing is 25 ± 5 °C and relative humidity 15% to 80%.
2. Voltage tolerance is 1.0% and maximum THD 2.0% at 1,500 W or less; 4.0% and 5.0% above 1,500 W.
3. The analyzer reports true RMS power with 1% or better accuracy, 3.0 kHz minimum frequency response, crest factor of at least 3 and calibration within a year.
4. The temperature sensor is within 50 mm of the air inlet, accurate to ± 0.5 °C, logging at least 4 samples per minute.
5. Products are tested as shipped; no UPS may sit between meter and unit, and all PSUs must be connected and operating.
6. Blade power is measured at the chassis input; half-populated chassis is required and full population is optional.
7. Multi-node systems are tested in a fully populated chassis, with idle power divided by the number of nodes.
8. The Ethernet link must be live, and 802.3az capable products connect only to compliant equipment.

Using it in design

• When importing server power data, keep the 25 ± 5 °C test ambient as metadata and warn that fan power rises at higher inlet set points.
• Model blade and multi-node catalogue items at chassis level, matching the measurement boundary (chassis input for blades).
• State the test configuration (half-populated blade chassis, per-node division) in the record before scaling to a fully populated chassis.
• Note in the measurement-boundary field that PDU overhead is included in the reading and UPS losses are not.

Who should read it

Design engineers who use server power and efficiency data in catalogues or load models, and ENERGY STAR test laboratories.

Document contents

1. 1 Overview
2. 2 Applicability
3. 3 Definitions
4. 4 Test Setup (input power, ambient temperature, relative humidity, power analyzer, temperature sensor, active state test tool, controller system)
5. 5.1 Test Configuration
6. 5.2 UUT Preparation
7. Blade chassis population rules (half and full)
8. 6 Test Procedures for All Products
9. 6.1 Idle and Active State Testing Using SERT

Related standards

• SPEC SERT 2.x
• ENERGY STAR Computer Servers V4.0

Read the document

Publication details

Authors

U.S. Environmental Protection Agency; U.S. Department of Energy

Publisher

U.S. Environmental Protection Agency (ENERGY STAR)

Year

2023

Document number

Rev. Jan-2023

Document language

English

Source type

Government / public

Access

Open licence — downloadable

Licence

U.S. public domain — U.S. Government work; free to reuse

Licence evidence

www.copyright.gov

Citation