Qualifying Criteria for Computer Servers

Version 1.0

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Products imported into and sold in Canada must meet all Canadian regulatory and safety requirements.

Eligible equipment must be qualified by the U.S. ENERGY STAR Program at the Environmental Protection Agency (EPA).

This technical specification is the same as the product specification published on the U.S. ENERGY STAR Web site and is provided as information only. Administered by Natural Resources Canada’s Office of Energy Efficiency, the ENERGY STAR Program in Canada uses the term Participant to designate companies, organizations and other stakeholders that promote the use of the ENERGY STAR mark on products or in promotional and marketing material and activities. This technical specification was modified to include this change. The use of the term Participant is similar in scope to that of Partner, which is used by the U.S. ENERGY STAR Program.

In order to promote ENERGY STAR qualified servers in Canada manufacturers are required to sign a Memorandum of Understanding (MOU) with the US EPA. We encourage manufacturers, retailers and distributors to sign a Participant Administrative Arrangement with Natural Resources Canada to take advantage of promotional and communications opportunities provided by the program.

Also, EPA and Natural Resources Canada both reserve the right to revise the specification should technological and/or market changes affect its usefulness to consumers or industry or its impact on the environment.

In order to be marketed and sold as ENERGY STAR, a product must meet all of the identified criteria as shipped to the customer, including all hardware or software alterations made to the product prior to sale.

This specification along with its complement, the specification for computers, intends to comprehensively cover a wide range of computer products. Manufacturers shall carefully examine their product designs and compare them to the detailed definitions (Section 1) and qualifying product descriptions (Section 2) for Computer Servers and Computers (visit the U.S. ENERGY STAR Web site at to determine the appropriate specification for ENERGY STAR qualification. Manufacturers may only qualify models under the one specification (i.e., Computer Servers OR Computers) that best reflects the product design.

1) Definitions

  • A. Computer Server
    A computer that provides services and manages networked resources for client devices, e.g. desktop computers, notebook computers, thin clients, wireless devices, PDAs, IP telephones, other Computer Servers and other networked devices. Computer Servers are sold through enterprise channels for use in data centers and office/corporate environments. Computer Servers are designed to respond to requests and are primarily accessed via network connections, and not through direct user input devices such as a keyboard, mouse, etc. In addition, Computer Servers must have all of the following characteristics:

    • Marketed and sold as a Computer Server;
    • Designed for and listed as supporting Computer Server Operating Systems (OS) and/or hypervisors, and targeted to run user-installed enterprise applications;
    • Support for error-correcting code (ECC) and/or buffered memory (including both buffered DIMMs and buffered on board (BOB) configurations);  
    • Packaged and sold with one or more AC-DC or DC-DC power supply(s); and
    • All processors have access to shared system memory and are independently visible to a single OS or hypervisor.
  • B. Blade System
    A system composed of both a Blade Chassis and one or more removable Blade Servers or Blade Storage units. Blade Systems are designed as a scalable solution to efficiently package and operate multiple Computer Servers or Storage units in a single enclosure, and are designed for technicians to be able to easily add or replace hot-swappable Computer Server boards (e.g., Blade Servers) in the field.

  • C. Blade Chassis
    An enclosure containing shared resources for the operation of Blade Servers and Blade Storage units. These resources may include power supply(s) for power conversion, shared storage, and hardware for DC power distribution, thermal management, system management, and network services. A Blade Chassis features multiple slots which can be populated with blades of different types.

Computer Server Types

  • D. Blade Server
    A Computer Server consisting of, at minimum, a processor and system memory that relies on shared resources (e.g., power supplies, cooling, etc.) for operation. Blade Servers are designed to be installed in a Blade Chassis, are hot-swappable and are incapable of operating independent of the chassis.

  • E. Direct Current (DC) Server
    A Computer Server with one or more DC-DC power supplies which runs directly off of DC power.

  • F. Fully Fault Tolerant Server
    A Computer Server designed with complete redundancy, in which every computing component is replicated between two nodes running identical and concurrent workloads. If one node fails or needs repair, the second node can run the workload alone to avoid any downtime. A Fully Fault Tolerant Server uses two systems to simultaneously and repetitively run a single workload for continuous availability in a mission critical application.

  • G. Managed Server
    Computer Servers designed for a high level of availability in a highly managed environment. A Managed Server must have all of the following characteristics:

    • Capability to operate with redundant power supplies; and
    • An installed dedicated management controller (e.g., service processor).  
  • H. Dual-Node Servers
    A Dual-Node Server consists of two independent Computer Servers (or nodes) contained in a single enclosure and sharing one or more power supplies. The combined power for all nodes is distributed through the shared power supply(s). Dual-Node Servers are designed and built as a single enclosure and are not designed to be hot-swappable.

  • I. Multi-Node Server
    For purposes of this specification, a Multi-Node Server consists of more than two independent Computer Servers (or nodes) contained in a single enclosure and sharing one or more power supplies. The combined power for all nodes is distributed through the shared power supply(s). Multi-Node Servers are designed and built as a single enclosure and are not designed to be hot-swappable.  

  • J. Server Appliance
    A self-contained Computer Server system bundled with a pre-installed operating system and application software that is used to perform a dedicated function or set of tightly coupled functions. Server Appliances deliver services through one or more networks (e.g, IP or SAN), and are typically managed through a web or command line interface. Server Appliance hardware and software configurations are customized by the vendor to perform a specific task, and are not intended to execute user-supplied software. Example services that may be made available via a Server Appliance include: name services, firewall services, authentication services, encryption services, and voice-over-IP (VoIP) services.

Other Data Center Equipment

  • K. Blade Storage
    A storage-specific element that relies on shared resources (e.g., power supplies, cooling, etc.) for operation. Blade Storage units are designed to be installed in a Blade Chassis, are hot-swappable and are incapable of operating independent of the chassis.

  • L. Network Equipment
    A product whose primary function is to provide data connectivity among devices connected to its several ports. Data connectivity is achieved via the routing of data packets encapsulated according to Internet Protocol, Fibre Channel, InfiniBand or similar protocol. Examples of network equipment commonly found in data centers are routers and switches.

  • M. Storage Equipment
    A system composed of integrated storage controllers, storage devices (e.g., hard drives or solid state storage) and software that provides data storage services to one or more Computer Servers. While storage equipment may contain one or more embedded processors, these processors do not execute user-supplied software applications but may execute data-specific applications (e.g., data replication, backup utilities, data compression, install agents, etc.).

Computer Server Components

  • N. Computer Server Power Supply Unit (PSU)
    A self-contained Computer Server component which converts a voltage input to one or more DC voltage outputs for the purpose of powering the Computer Server. The input voltage can be from either an AC or DC source. A Computer Server power supply must be separable from the main computer board and must connect to the system via a removable or hard-wired male/female electrical connection, cable, cord or other wiring (i.e. separate from, and not integrated with, the system motherboard).

  • O. AC-DC Power Supply
    A power supply which converts line voltage AC input power into one or more different DC outputs for the purpose of powering the Computer Server.

  • P. DC-DC Power Supply
    A power supply which converts a DC voltage input to one or more different DC voltage outputs for the purpose of powering the Computer Server. Any DC-to-DC converters (also known as voltage regulators) internal to the product and used to convert low DC voltage (e.g. 12 Volts DC) into other DC voltages for use by Computer Server components are not considered DC-DC power supplies under this specification.

  • Q. Single-Output Power Supply
    A power supply which delivers most of its rated power through one primary DC output for the purpose of powering the Computer Server. Single-Output power supplies may include one or more standby outputs which remain active whenever connected to an input power source. There may be additional outputs besides the primary output and standby outputs, however, the combined power from all additional outputs must be no greater than 20 watts.
    Note: Power supplies with multiple outputs at the primary voltage are considered a Single-Output Power Supply, unless these outputs are either, (1) generated from separate converters or have separate output rectification stages, and/or (2) have independent current limits.

  • R. Multi-Output Power Supply
    A power supply which delivers its power through more than one primary output, including one or more standby outputs which remain active whenever connected to an input power source. For Multi-Output Supplies, the combined power from additional outputs other than the primary and standby outputs is greater than 20 watts. This definition also applies to power supplies with multiple outputs at the same voltage that do not meet the definition of a Single-Output Power Supply, above.

  • S. I/O Devices
    Devices which provide data input and output capability to the Computer Server from other devices. I/O Devices can either be integral to the main computer board or can be separate devices connected though expansion slots such as PCI or PCIe. Examples of I/O Devices include: Ethernet devices, InfiniBand devices, external RAID/SAS controllers and Fibre Channel devices.

  • T. I/O Port
    Physical circuitry within an I/O Device where an independent I/O session can be established. A port is not the same as a connector receptacle; it is possible that a single receptacle that accepts a single connector can service multiple ports of the same interface.

Other Key Terms

  • U. Idle
    An operational state in which the operating system and other software have completed loading and the Computer Server is capable of completing workload transactions, but no active workload transactions are requested or pending by the system (i.e., the Computer Server is operational, but not processing any useful work).

  • V. Product Family
    A group of Computer Server configurations where every configuration includes base components with the same or similar technical specifications and power specifications. In order to be considered a Product Family, all configurations must:

    • Use the same model motherboard;
    • Use the same number of processors. All processors must be represented by the same model line and have identical power specifications and core counts (e.g., processors may vary in speed within the same power specification within a given model line); and
    • Incorporate the same model, with the same technical and power specifications, for the base components listed below (the relative numbers of these components may vary within the family):
      • - Power supplies,
      • - Memory DIMMs,
      • - Hard drives (including solid state drives) , and
      • - I/O Devices.

    A configuration without add-in I/O Devices may be included in a Product Family with any number of additional I/O Devices included in other configurations. In addition, a configuration otherwise identical to the minimum configuration, but without an internal hard drive may also be included in a product family.

  • W. Maximum Configuration
    The Maximum Configuration is a highly configured system that includes the combination of power supplies, memory, hard drives, I/O Devices, etc. which provide the maximum possible power consumption within a Product Family.

  • X. Minimum Configuration
    The Minimum Configuration is a minimally configured system that represents the lowest possible power consumption within a Product Family, for configurations with at least one hard drive. Such a system would typically have the minimum number of power supplies, the least amount of system memory, a single hard drive, and a single I/O Device (either integrated or add-in). The Minimum Configuration must be currently available and sold in the marketplace (i.e. the system shall be minimally configured but not under-configured to a point which is unreasonable).

  • Y. Typical Configuration
    An intermediate configuration between the Maximum Configuration and Minimum Configuration of a Product Family. The Typical Configuration shall be representative of a configuration with high volume sales which contains a typical number of hard drives and I/O Devices, an average amount of installed memory, etc.

  • Z. Base Configuration
    The base configuration is a reference configuration which does not qualify for any additional power allowances. Any applicable components above the level defined by the base configuration may qualify for additional power allowance(s) as described in Table 4, below. The base configuration includes:

    • One hard drive (or solid state drive),
    • Four Gigabytes (GB) of system memory,
    • The minimum number of power supplies required to operate the Computer Server (i.e. no redundant power supplies), and
    • Two ports of 1 Gigabit (Gbit), onboard Ethernet.

2) Qualifying Products

A Computer Server must meet the definition provided in Section 1.A, above, to be eligible for ENERGY STAR qualification under this specification. The Tier 1 specification coverage is limited to Computer Servers having at most four processor sockets (i.e. Computer Servers with 1 - 4 individual processor sockets). Computer Servers with more than four processor sockets are currently ineligible for ENERGY STAR qualification under the Tier 1 specification but will be considered for inclusion under Tier 2 requirements.

In addition to those products that do not meet the strict definition provided in Section 1.A, the following product types (as defined in Section 1, above) are explicitly ineligible for ENERGY STAR qualification:

  • Blade Systems including Blade Servers and Blade Chassis,
  • Fully Fault Tolerant Servers,
  • Server Appliances,
  • Multi-Node Servers,
  • Storage Equipment including Blade Storage, and
  • Network Equipment.

Tier 2 Coverage : For the Tier 2 specification, EPA intends to expand the coverage of this specification, and will investigate including the additional Computer Server types excluded in this Tier 1 specification, including: systems with greater than four sockets, Blade Systems, Fully Fault Tolerant Servers, Server Appliances, and Multi-Node Servers. EPA also intends to investigate covering Storage Equipment and Networking Equipment under separate future specifications.

3) Efficiency Requirements for Qualifying Products

A Computer Server must meet all the requirements provided in Sections 3.A – 3.D, below, to qualify as ENERGY STAR.

Tier 1 Requirements: Effective May 15, 2009

  • A. Power Supply Efficiency Requirements

    All power supplies used in Computer Servers eligible under this specification must meet the minimum efficiency requirements presented in Table 1, below.

    Table 1: Efficiency Requirements for Computer Server Power Supplies

    Power Supply Type

    Rated Output Power

    10% Load

    20% Load

    50% Load

    100% Load

    (AC-DC & DC-DC)

    All Output Levels





    (AC-DC & DC-DC)

    ≤ 500 watts





    > 500 - 1,000 watts





    > 1,000 watts





    In addition, power supplies must meet the minimum power factor requirements for all loading conditions presented in Table 2, below, where the output power is greater than or equal to 75 watts. Manufacturers are still required to measure and report power factor values for applicable loading conditions less than 75 watts to qualify for ENERGY STAR.

    Table 2: Power Factor Requirements for Computer Server Power Supplies

    Power Supply Type

    Rated Output Power

    10% Load

    20% Load

    50% Load

    100% Load

    DC-DC (All)

    All Output Levels





    AC-DC Multi-Output

    All Output Levels





    AC-DC Single-Output

    ≤ 500 watts





    > 500 - 1,000 watts





    > 1,000 watts





  • B. Active Power Requirements

    1. Single and Dual Processor Socket Computer Servers (1S & 2S)
    Computer Servers with two or fewer processor sockets must have an Idle power consumption which does not exceed the allowed maximum Idle power levels determined from Tables 3 and 4, below, based on the components installed in the system. Please note the following:

    • These Idle power limits are applicable to single and dual socket systems only, regardless of the number of processors (e.g., a three or four socket system with only one or two processors installed would not be subject to this requirement); and
    • All quantities in Tables 3 and 4 refer to the number of components installed in the system , not the maximum number of components the system can support (e.g. installed processors, not processor sockets; installed memory, not supported memory; etc.).

    Table 3 presents the Idle power allowance for base or lower configurations. One and two processor (1P & 2P) Computer Servers meeting the definition for Managed Servers in Section 1.G, above, must use the Managed Server Idle levels for Category B and Category D in Table 3, below. Any one or two processor Computer Server not meeting the definition for Managed Servers (i.e. “Standard” servers) must meet the Standard Server levels for Category A and C in Table 3, below.

    Note: The levels provided in Table 3 below are for Computer Servers that must be tested and qualified with a minimum of one hard drive. Computer Servers sold without a hard drive may still qualify as ENERGY STAR if the configuration was originally tested and qualified with a single hard drive installed. In this case, the qualified configuration when shipped without a hard drive may also be marketed and sold as ENERGY STAR.

    Table 3: Base Configuration Idle Power Requirements

    Computer Server Type

    Idle Power Limit

    Category A: Standard Single Installed Processor (1P) Servers

    55.0 watts

    Category B: Managed Single Installed Processor (1P) Servers

    65.0 watts

    Category C: Standard Dual Installed Processor (2P) Servers

    100.0 watts

    Category D: Managed Dual Installed Processor (2P) Servers

    150.0 watts

    Table 4 presents additional Idle power allowances for Computer Servers with additional capabilities above that of a base configuration. The maximum Idle power level should be determined by applying as many additional power allowances as are appropriate.

    Table 4: Additional Idle Power Allowances for Extra Components

    System Characteristic

    Applies To:

    Additional Idle Power Allowance

    Power Supplies

    Power supplies installed explicitly for power redundancy1

    20.0 watts per Power Supply

    Additional Hard Drives
    (including solid state drives)

    Installed hard drives greater than one

    8.0 watts per Hard Drive

    Additional Memory

    Installed memory greater than 4 GB2

    2.0 watts per GB2

    I/O Devices

    Installed Devices greater than two ports of 1 Gbit, onboard Ethernet3

    < 1Gbit4: No Allowance
    = 1 Gbit4: 2.0 watts / Active Port5

    > 1 Gbit4 and < 10 Gbit4: 4.0 watts / Active Port5
    ≥ 10 Gbit4: 8.0 watts / Active Port5

    * Notes on Additional Power Allowances:

    1. Idle power allowances are granted for power supplies in addition to the minimum number needed to operate the Computer Server. For example, if a Computer Server requires two power supplies to operate, and the configuration includes three power supplies, the server would receive an additional 20.0 watt Idle power allowance. If the same server were instead shipped with four power supplies installed, it would receive an additional Idle power allowance of 40.0 watts.
    2. For the purposes of determining Idle power allowances, all memory capacities shall be rounded to the nearest GB.
    3. Idle power allowances are granted for all I/O Devices over the base configuration listed in Section 1.Z, including all add-in devices installed through expansion slots and all onboard devices above the base configuration.
    4. I/O Device allowances are dependant on the rated link speed of a single connection, with speeds rounded to the nearest Gbit. Devices with speeds less than 1 Gbit do not qualify for any additional I/O Device allowances.
    5. In order to claim an additional allowance, I/O Devices must be active (enabled) upon shipment and must be capable of functioning when connected to an active switch.

    To determine the maximum Idle power consumption levels for ENERGY STAR qualification, manufacturers shall use the base configuration Idle level from Table 3, based on installed processors and level of manageability, and then add power allowances from Table 4, where appropriate. An example is provided below.

    Example: A standard single processor Computer Server with 4 GB of memory and a single hard drive could consume no more than 55.0 watts in Idle to qualify for ENERGY STAR. The same Computer Server with an additional hard drive would be provided with an additional 8.0 watt allowance and therefore, could consume no more than 63.0 watts of Idle power to qualify. If this server was then upgraded to 8.0 GB of memory, it would be granted another 8.0 watts (4 extra GB x 2.0 watts/GB) and would be expected to consume no more than 71.0 watts Idle power to qualify.

    Dual-Node Servers: Dual-Node Servers with one or two sockets per node must meet the above Idle power levels on a per node basis, provided each node in the system is identical in configuration and uses identical components . In this case, the Idle power per node would be found by measuring the combined Idle power of the whole unit (including both Computer Server nodes), as outlined in the Idle power test procedure in Appendix A of this specification, and dividing that total Idle power by two. For example, if two Computer Server nodes share a single power supply, the combined Idle power of the two Computer Servers (measured through the single power supply) would be measured and then the result would be divided by two. The resulting Idle power per node would need to meet the requirements presented in Tables 3 and 4, above, based on the per node configuration, to qualify for ENERGY STAR. However, the full Idle power of the complete system (including both nodes) must also be reported on the Power and Performance Data Sheet, as presented in Section 3.C of this specification.

    2. Computer Servers with Greater than Two Processor Sockets (3S & 4S)

    All three and four socket Computer Servers must enable processor level power management to reduce power use of the processor during times of low utilization such as Idle, and these systems are not subject to Idle power limits under this Version 1.0 specification. Systems must be shipped with this power management functionality enabled in the system BIOS, and/or a management controller or service processor. All systems shipping with a preinstalled supervisor system (operating system or hypervisor) must also have this power management functionality enabled by default in the supervisor system. This requirement is not applicable to 1S and 2S Computer Servers, though manufacturers are encouraged to use these techniques in 1S and 2S Computer Servers to reduce power consumption in Idle.

    In order to meet this requirement, all processors must be able to reduce power consumption in times of low utilization, by either:

    • Reducing voltage and/or frequency through Dynamic Voltage and Frequency Scaling (DVFS), or
    • Using processor or core reduced power states when a core or socket is not being used.

    As with all Computer Servers covered under this specification, Participants must disclose all power management techniques that are enabled upon product shipment on the Power and Performance Data Sheet described in Section 3.C of this specification.

    Dual Node Servers: Dual-Node Servers with three or four sockets per node must also meet this processor power management requirement.

  • C. Standard Information Reporting Requirements

    Participants must provide a standardized Version 1.0 Power and Performance Data Sheet with each ENERGY STAR qualified Computer Server. This information must be posted on the Participants’ Web site where information on the qualified model, or qualified configurations, is posted. Participants are encouraged to provide one data sheet per qualified configuration, but may also provide one data sheet per Product Family (as defined in Section 1.V above) with data on the Computer Server’s power and performance in Maximum, Minimum and Typical configurations as defined in Sections 1.W through 1.Y.

    If one data sheet is used to represent many configurations under one Product Family, Participants shall, when available, also provide a link to a more detailed power calculator where information on the power consumption of specific system configurations can be found.

    Templates for the Version 1.0 Power and Performance Data Sheet can be found on the U.S ENERGY STAR Web page for Computer Servers at Participants are encouraged to use the referenced data sheet template, but may also create their own template provided that it is identical in format and design as the referenced template, and has been approved by EPA. EPA may periodically revise this template, as necessary, and will notify Participants of the revision process. Participants should always use the most recent version of the data sheet posted to the U. S. ENERGY STAR Web site.

    Each Power and Performance Data Sheet must include the following information:

    1. Model name and number, identifying SKU and/or configuration ID;
    2. System characteristics (form factor, available sockets/slots, power specifications, etc.);
    3. System configuration(s) (including maximum, minimum and typical configurations for product family qualification);
    4. Power data for Idle and full load, estimated kWh/year, link to power calculator (where available);
    5. Additional power and performance data for at least one benchmark chosen by the Participant;
    6. Available and enabled power saving features (e.g., power management);
    7. Information on the power measurement and reporting capabilities of the Computer Server;
    8. Select thermal information from the ASHRAE thermal report; and
    9. A list of additional qualified SKUs or configuration IDs, along with specific configuration information (for Product Family qualification only).
  • D. Data Measurement and Output Requirements

    Standardized Data Measurement
    One and two socket (1S and 2S) Computer Servers which meet the definition of a Managed Server in Section 1.G and all Computer Servers with greater than two sockets (3S and 4S) must have the ability to provide data on input power consumption in watts, inlet air temperature, and utilization of all logical CPUs during normal operation. Single socket and dual socket (1S and 2S) products that do not meet the definition of a Managed Server are exempt from this requirement.

    To meet the data measurement and output requirements, Computer Servers may rely on a service processor, embedded power or thermal meter (or other out-of-band technology shipped with the Computer Server), or preinstalled operating system to collect data and make it available for collection and dissemination over a standard network to third-party management systems such as a data center management software suite. Data must be made available in a published or user accessible format so as to be readable by third-party, non-proprietary management systems. All systems shipped with preinstalled operating systems must have all necessary drivers/software installed to make this information openly available. For systems not shipped with an operating system, documentation of how to access the registers containing the relevant sensor information must be provided in user manuals and online documentation. In addition, when an open and universally available standard becomes available to report and collect this data, manufacturers should incorporate the universal standard into their systems. Computer Servers may meet this requirement through embedded components or add-in devices included with the server on shipment.

    Measurement Accuracy:

    • Input power measurements: EPA recommends the following Accuracy requirements for input power measurements on a system level:
      ±10% accuracy with a cut-off at ± 10 watts (i.e. accuracy never needs to be better than ± 10 watts).

      Tier 2 Requirements As indicated in the Tier 2 requirements, ± 5% accuracy with a cut-off of ± 5 watts (i.e. accuracy is never required to be better than ± 5 watts) will be required in the Tier 2 specification. Note: The above accuracy levels are solely in reference to the Power Measurement and Output Requirements included in this section. Accuracy requirements for Idle power and full load power tests are included in the test procedure in Appendix A of this specification.

    • Processor utilization measurements: The Computer Server will provide an estimation of the processor utilization that is visible to the operator or user of the Computer Server through the operating environment (operating system or hypervisor). This estimation is not subject to specific accuracy requirements under this Tier1 specification.

    • Inlet air temperature measurements: Computer Servers must meet an accuracy of ± 3° C on all air temperature measurements.

    Sampling Requirements: Data must be averaged on either a rolling basis or over a manufacturer specified time period. A default rolling average or time period of 30 seconds is recommended.

  • Reporting Requirements: Manufacturers must report the following on the Power and Performance Data Sheet:

    • Guaranteed accuracy levels for power and temperature measurements, and

    • The time period used for data averaging.

    Tier 2 Requirements: Effective October 15, 2010

    (1a) Tier 2: TBD

    – OR –

    (1b) Provisional Tier 2 Idle State Requirements. If an energy efficiency performance metric and associated performance levels are not available for an October 15, 2010 Tier 2 effective date , a provisional Tier 2 specification will automatically go into effect and will remain in effect until such a metric is established under a subsequent Version or Tier. This provisional Tier 2 would include revised Idle power consumption requirements for all Computer Server types covered by Tier 1 of this specification. The new levels will be developed with the intention of capturing approximately the top 25% of products available in the marketplace at the time Tier 2 becomes effective. EPA may also consider developing Idle levels for product types currently excluded from this Tier 1 specification (Section 2: Qualifying Products). Development of a Provisional Tier 2, as well as all subsequent Versions or Tiers, will be done in accordance with ENERGY STAR’s product development guidelines.

    (2) Power Supply Requirements: EPA intends to explore a Net Power Loss approach for Computer Server power supplies under Tier 2 of this specification. This approach would aim to specify a maximum allowed power loss through the power supply at actual operating conditions of the Computer Server (e.g., Idle and full load power). If a Net Power Loss approach is not developed, EPA plans to re-evaluate both Multi-Output and Single-Output power supply efficiency and power factor levels. At a minimum, EPA intends to eliminate the lower efficiency requirement for all Single-Output power supplies with less than or equal to 1000 W power output and requiring that all Single-Output power supplies meet the same efficiency levels (i.e., 80% efficiency at 10% load; 88% at 20% load; 92% at 50% load; and 88% at 100% load).

    (3) Data Measurement and Output Requirements: EPA will include more stringent accuracy requirements under Tier 2 of this specification. Tier 2 will include a definition for processor/system utilization, with corresponding accuracy levels, and requirements for power measurement accuracy.

    Accuracy requirements for power measurements will be ± 5% accuracy with a cut-off of ± 5 watt (i.e. accuracy is never required to be better than ± 5 watts). These accuracy levels will be at a system level and will have to be met only over the operating range of the Computer Server (i.e. measurements ranging from Idle to full load power).

    In addition, EPA will require the Data Measurement and Output Requirements presented in this Version 1.0 Computer Servers specification of all ENERGY STAR qualified Computer Servers covered by the Tier 2 specification. EPA also plans to require a rolling average of data encompassing no greater than 30 seconds under Tier 2.

    (4) Energy Efficient Ethernet: EPA plans to investigate the use of the Energy Efficient Ethernet (IEEE 802.3az) standard for all external physical layer Ethernet (e.g., 1 Gbit and 10 Gbit wired Ethernet) following its ultimate approval by IEEE. More information on the developing standard can be found on the U.S. ENERGY STAR Web site at

4) Test Criteria

Manufacturers are required to perform appropriate tests, as outlined below, in order to determine ENERGY STAR qualification for a given configuration or Product Family. These required tests include:

  • Power Supply Efficiency Testing as outlined in Section 4.A for power supply efficiency and power factor requirements and reporting on the Power and Performance Data Sheet for all Computer Servers.

  • Idle Testing as outlined in Section 4.B for Idle power requirements of Single and Dual socket Computer Servers, and for Idle power and full load power reporting of all Computer Servers on the Power and Performance Data Sheet.

The results of those tests may be self-certified by the ENERGY STAR Participant, or by a third-party laboratory on behalf of the Participant, and must be reported to EPA using the most current procedures put in place by EPA at time of submittal (e.g. Qualified Product Information [QPI] form or Online Product Submittal [OPS]). Models that are unchanged or that differ only in finish from those sold in a previous year may remain qualified without the submission of new test data assuming the specification remains unchanged.  

Tier 2 Accreditation Requirement for Testing Laboratories: EPA is working toward a quality assurance requirement for all testing conducted in support of qualification for ENERGY STAR. Ideally, Computer Servers would be tested in an accredited, independent laboratory. To meet this requirement, the testing laboratory would be accredited by an accreditation body that is a signatory, in good standing, to a mutual recognition arrangement of a laboratory accreditation cooperation (e.g., International Laboratory Accreditation Cooperation, ILAC, Asia Pacific Laboratory Accreditation Cooperation, APLAC) that verifies, by evaluation and peer assessment, that its signatory members are in full compliance with ISO/IEC 17011 and that their accredited laboratories comply with ISO/IEC 17025. The laboratory’s Scope of Accreditation would need to reflect their specific competence to carry out the test procedures in this Section 4 of the ENERGY STAR requirements for Computer Servers. Once finalized, EPA will include the new testing requirements under Tier 2, which will provide manufacturers with sufficient time to either obtain accreditation or locate an accredited third-party laboratory to conduct testing.

A. Power Supply Testing
Computer Server manufacturer Participants are required to guarantee power supplies have been tested and found to comply with the power supply efficiency levels in Section 3.A of this specification. Testing shall be conducted as follows:

  • A Computer Server power supply must be tested for ENERGY STAR qualification using the most recent version of the Generalized Internal Power Supply Efficiency Test Protocol maintained by the Electric Power Research Institute (EPRI) and found on the U.S. ENERGY STAR Web site at

Additional Guidance on Power Supply Testing

  1. Power supplies shall be tested using the input test conditions specified in Table 5, below, and as indicated in the above referenced test procedure. For AC-DC Multi-Output power supplies capable of operating at both 230 and 115 Volts input, testing shall be conducted at both inputvoltages for purposes of ENERGY STAR qualification. AC-DC Multi-Output power supplies capable of operating at only one of these indicated voltages must test only at the applicable voltage. Testing at 230 Volts may be done at either 50Hz or 60Hz.

    Table 5: Input Conditions for Power Supply Efficiency Testing

    Power Supply Type

    Input Test Conditions

    AC-DC Single-Output

    230 Volts, 50Hz or 60 Hz

    AC-DC Multi-Output

    115 Volts, 60 Hz and/or 230 Volts, 50Hz or 60Hz


    53 Volts DC or -53 Volts DC


  2. 10% Loading Condition: As referenced in the power supply efficiency requirements in Section 3.A, all Single-Output power supplies must be tested at 10% loading in addition to the standard 20%, 50% and 100% loading conditions indicated in the test procedure.

  3. Fan Power: As indicated in the power supply test procedure referenced above, Multi-Output power supplies must be tested with internal fan power included in the measurement and efficiency calculation. Single-Output power supplies must exclude fan power from the measurement and the efficiency calculation.

  4. Efficiency and Power Factor Reporting: Power supplies must meet the levels presented in Tables 1 and 2 without the assistance of rounding. When submitting power supply efficiency and power factor results, manufacturer shall report to the first decimal place (e.g. 85.2%) and three decimal points (e.g., 0.856), respectively.

B. Idle and Full Load Power Testing

Participants must use the ENERGY STAR Test Procedure for Determining the Power Use of Computer Servers at Idle and Full Load, included in Appendix A of this specification to measure Idle and full load power consumption for purposes of ENERGY STAR qualification. All single socket (1S) and dual socket (2S) Computer Servers must meet the Idle power levels presented in Tables 3 and 4 in section 3.B.1 depending on system configuration. The Participant must test and report Idle and full load power consumption test results for all Computer Servers, including three socket (3S) and four socket (4S) Computer Servers.

  1. Test as shipped: Computer Servers must be tested in their “as-shipped” configuration, unless otherwise indicated in the referenced test procedures. For power consumption testing, all power supplies must be connected and operational, and the as-shipped operating system or a representative operating system (see 4.B.3, below) must be installed. For all tests, manufacturers must ensure that the only power management techniques and/or power saving features enabled on systems under test are those which are also enabled on shipment.

  2. Computer Server shipped without a preinstalled hard drive: Computer Servers shipped without hard drives may carry the ENERGY STAR mark only if (1) an otherwise identical configuration was tested and qualified with at least one hard drive installed.

  3. Computer Servers shipped without a preinstalled operating system: For Computer Servers shipped without a pre-installed operating system, manufacturers must clearly indicate on the Power and Performance Data Sheet (Section 3.C) which operating system was used in testing for the purposes of ENERGY STAR qualification. In addition, as outlined in Appendix A, any power management features which require the presence of an operating system (i.e. those that are not explicitly controlled by the BIOS or management controller) must be tested using only those power management features enabled by the operating system by default. Manufacturers must also clearly indicate on the Power and Performance Data Sheet which power management features were active during testing.

  4. Idle Reporting: Computer Servers must meet the Idle power consumption levels determined from Tables 3 and 4 without the assistance of rounding. When submitting Idle results, manufacturer shall report power consumption to the first decimal place (e.g. 125.6 watts).

C. Qualifying Computer Servers Through Value Added Resellers (VARs)

In some cases, ENERGY STAR qualified Computer Servers may be shipped from the Original Equipment Manufacturer (OEM) to a VAR that then determines the end configuration which is ultimately sold to the end user. In order for the VAR to sell the Computer Server as ENERGY STAR qualified under the OEM brand name, one of two conditions must be met:

  1. The end configuration sold by the VAR must have been originally qualified by the OEM, or
  2. In the case that the end configuration has not been qualified by the OEM, the VAR must become an ENERGY STAR Participant, and test and qualify the configuration.

OEM Participant selling Computer Servers to VARs must provide the VAR with a list of qualified configurations for that model, using approved components, which have been initially qualified and reported to EPA by the OEM Participant.

Ultimately, the party (i.e. the OEM or VAR) that markets and sells the ENERGY STAR Computer Server to the end user is responsible for ensuring the configuration has been qualified either by the party itself or by the OEM. If a VAR markets and sells a Computer Server under one of its own brands, that VAR must become an ENERGY STAR Participant and qualify the Computer Server under their own brand name.

D. Qualifying Configurations and Families Under this Specification

Participant are encouraged to test and submit qualified product data on all individual configurations for ENERGY STAR. However, a Participant may qualify multiple configurations under one Product Family designation as long as all of the configurations within that Product Family meet one of the following requirements:

  • Subsequent units are built on the same platform and are identical in every respect to the tested, representative model except for housing and color.

  • Subsequent units meet the requirements of a Product Family, as defined in Section 1.V, above. In this case, Participants must test and submit power data on a maximum and minimum configuration, as defined in Sections 1.W and 1.X of this specification. Participants are also required to include a Power and Performance Data Sheet for each Product Family as described in Section 3.C of this specification.

All configurations associated with a Product Family, for which a Participant is seeking ENERGY STAR qualification, must meet the ENERGY STAR requirements, including those for which data was not reported. If a Participant wishes to qualify individual configurations within a Product Family for which non-qualifying configurations exist, the Participant must assign the qualifying configurations an identifier in the model name/number that is unique to ENERGY STAR qualified configurations. This identifier must be used consistently in association with the qualifying configurations in marketing/sales materials and on the ENERGY STAR list of qualified products (e.g. model A1234 for baseline configurations and A1234-ES for ENERGY STAR qualifying configurations).

5) Effective Date

The date that manufacturers may begin to label and promote qualifying products as ENERGY STAR will be defined as the effective date of the agreement.

  1. Tier 1 Requirements: The first phase of this specification will commence on May 15, 2009 . For products sold in the European Union, the effective date will be on the 20th day following its publication in the Official Journal of the European Union.

  2. Tier 2 Requirements: The second phase of this specification, Tier 2, will commence on October 15, 2010 . All products, including models originally qualified under Tier 1, with a date of manufacture on or after October 15, 2010 , must meet the Tier 2 requirements in order to qualify for ENERGY STAR.

6) Future Specification Revisions

EPA and Natural Resources Canada reserves the right to change the specification should technological and/or market changes affect its usefulness to consumers, industry, or the environment. In keeping with current policy, revisions to the specification are arrived at through industry discussions. In the event of a specification revision, please note that ENERGY STAR qualification is not automatically granted for the life of a product model. To carry the ENERGY STAR mark, a product model must meet the ENERGY STAR technical specifications that are in effect on the date of product manufacture.

Next: Appendix A