Purchasing Guidelines for servers and network equipment
Servers and network equipment account for a large proportion of the total electricity consumption in office buildings because equipment is generally always on.
Purchasing guidelines for small-scale servers – good advice for larger ones
Network equipment and servers account for a large proportion of the total electricity consumption in office buildings because equipment is generally always on. The Trust has only laid down purchasing guidelines for small-scale servers. For larger servers and connected equipment, we recommend that you follow the advice on purchasing and operating equipment listed below. The Trust has, however, laid down requirements for Uninterruptible Power Systems (UPS).
Servers and network equipment are divided into:
- UPS: Power protection for servers.
- Small-scale servers: Servers for homes and small offices.
- Recommendations for server rooms and data centres.
- Network and broadband equipment: Routers, switches, VoIP telephones, etc.
Purchasing requirements: Servers
Requirements conform to: Energy Star Version 1.0 Program Requirements for Computer Servers.
The requirements cover servers with up to 4 processor sockets. Blade servers, storage area networks (SANs), etc. are not covered by the requirements.
The requirements comprise:
- Efficiency requirements for computer server power supplies (see below).
- Idle power requirements for servers with up to 2 processor sockets (see below).
- Power supply efficiency requirements for computers with greater than 2 processor sockets (3S & 4S).
- Requirements for data collection by "managed" types of single and dual processor-socket servers, and all 3 and 4 processor-socket servers.
Efficiency Requirements for Computer Server Power Supplies
| Power supply type | Rated output power | 10% load | 20% load | 50% load | 100% load |
| Multi-output (AC-DC & DC-DC) | - | N/A | 82% | 85% | 82% |
| Single-output (AC-DC & DC-DC) | ≤ 500 watts > 500-1000 watts > 1000 watts |
70% 75% 80% |
82% 85% 88% |
89% 89% 92% |
85% 85% 88% |
See notes and further definitions
Base configuration idle power requirements
| Computer server type | Idle power limit in watts |
| Category A: Standard (1 CPU) servers | 55.0 watt |
| Category B: Managed (1 CPU) servers | 65.0 watt |
| Category C: Standard (2 CPU) servers | 100.0 watt |
| Category D: Managed (2 CPU) servers | 150.0 watt |
Requirements apply to servers with up to 2 or fewer processor sockets. See notes and further definitions
Requirements for additional idle power allowances for extra components:
| System characteristic | Applies to: | Additional idle power allowance in watts |
| Additional power supplies | Power supplies installed explicitly for power redundancy | 20.0 watts per power supply |
| Additional hard drives | Installed hard drives greater than 1 | 8.0 watts per hard drive |
| Additional memory | Installed memory greater than 4 GB | 2.0 watts per GB |
| Additional I/O devices* | Installed devices greater than 2 ports of 1 Gbit onboard Ethernet | < 1 Gbit: no allowance 1 Gbit: 2 watts / active port > 1 Gbit and < 10 Gbit: 4.0 watts / active port ≥ 10 Gbit: 8.0 watts / active port |
* I/O devices must be active (enabled) upon shipment to qualify as an additional device.
Requirements apply to servers with up to 2 or fewer processor sockets. See notes and further definitions.
Note: Servers with greater than 2 processor sockets must reduce power during times of low utilization. See notes and further definitions.
Purchasing requirements: Uninterruptible Power Systems (UPS)
Uninterruptible Power Systems provide power protection for servers.
Requirements conform to: EU Uninterruptible Power Systems Code of Conduct Version 1.0a, January 2008.
| UPS power mode | UPS double conversion in basic configuration (VFI-S) | VI and VFI UPS (except VFI-S) | VFD UPS | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Energy efficiency requirements at 100% of nominal output | Energy efficiency requirements at 100% of nominal output | Energy efficiency requirements at 100% of nominal output | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| 10 ≤ power < 20 kVA | 91.0% | 92.5% | 96.0% | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| 20 ≤ power < 40 kVA | 91.5% | 93.0% | 96.5% | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| 40 ≤ power < 200 kVA | 92.0% | 93.5% | 97.0% | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| 200 kVA ≤ power | 93.0% | 94.5% | 98.0% | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Requirements covering other power levels (25%, 50% and 75% of nominal power (see notes). | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Requirements cover Uninterruptible Power Systems (UPS) per EN 62040-3 ed. 1.0 b:1999, which supply three phase electricity over 10 kVA at 400/230 V. The energy efficiency is the minimum permissible for energy efficient equipment and is measured in normal mode in relation to EN 62040-3 ed. 1.0 b:1999 (Appendix AA). See notes and further definitions
Note: Additional reduction in energy efficiency is allowable when using additional isolation transformers and equipment to achieve harmonic current.
Purchasing requirements: Small-scale servers
Computers designed to provide server functions in homes and small offices. Requirements conform to Energy Star program requirements for computers Version 5.0.
| Type | On (at idle) | Off watts | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Small-scale servers for home and office use | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| – Server, smaller than definition below | 50.0 | 2 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| – More powerful server (minimum 1 GB RAM with greater than 1 physical core or greater than 1 discrete processor) | 65.0 | 2 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Requirements for external and internal power supplies as per computers | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Must be shipped with display’s Sleep mode set to activate within 15 minutes of user inactivity | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Small-scale servers with Ethernet capability must be able to activate or deactivate Wake On LAN (WOL) in sleep mode | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Requirements cover computers designed to provide server functions in homes and small offices. Power consumption is the maximum permitted for energy efficient equipment. See notes and further definitions.
Note: Small-scale servers shipped with Wake On LAN (WOL) activated are allowed +0.7 W in Off mode.
Recommendations for server rooms and data centres
Recommendations conform to the latest version of the EU Code of Conduct for energy efficient data centres.
| Type | Recommendations |
| Server rooms and data centres | Follow guidelines in EU Code of Conduct for energy efficient data centres for measurement of energy consumption, identification of potential savings and implementation of savings. Enter voluntary agreements with the EU Commission on energy efficient data centres (applies to large primary data centres) |
| Institutions which purchase server capacity from Data centres | Enquire about (in tender material, etc.) and select supplier which follows the guidelines described in the EU Code of Conduct on Energy Efficient Data Centres. Enquire about, and select a supplier which has concluded a voluntary agreement with the EU Commission on energy efficient data centres (applies to large primary data centres) |
Recommendations apply to owners of server rooms and data centres, and institutions which purchase server capacity from data centres.
Purchasing requirements: Network and broadband equipment
Requirements conform to EU Broadband Equipment Code of Conduct – Version 3, 18 November 2008.
| Type | On watts | Low energy state watts | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
Broadband equipment. Basic functions and WAN interface |
2.0 |
2.0 |
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| Other LAN technologies (HPNA, MoCA, etc.) - Wi-Fi Access points (single band IEEE 802.11b/ g or 11a - Wi-Fi Access points (single band IEEE802.11n Draft 2 radio etc.) - Wi-Fi Access points with dualt (2.4 and 5 GHz) band IEEE 802.11n Draft 2 radio, etc. - Small hubs and non stackable Layer 2-switches (up to 8 Ethernet ports 10/100/1000 Mbit/s) without CPU - Optical Lan-adapter (10/100/1000 Mbit/s) - Powerline-adapters - Other LAN technologies (HPNA, MoCA, etc.) |
4.0 6.0 10.0 8.0 4.0 5.0 5.0 |
3.0 4.5 7.0 3.0 4.0 4.5 5.0 |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Other network devices - ATA/VoIP gateway - VoIP telephone - Printer server (without Wi-Fi) |
2.7 4.2 4.5 |
2.0 3.5 3.0 |
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| External power supplies must conform to the Trust's requirements | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Requirements cover home broadband equipment (components, etc.) and network equipment for home use. Power consumption is the maximum permitted for energy efficient equipment. See notes and further definitions.
Note: Additional consumption by broadband equipment is allowable if equipment provides supplementary functions over and above basic functions such as Ethernet switch, Wi-Fi, USB, Bluetooth, etc. Additional consumption not permitted for USB DSL modems.
Good advice on purchasing and operating equipment
- A large amount of electricity can be saved for server equipment and in the server room. Typically, by saving 1 kWh on the server equipment, you can save 1.5 kWh for the whole server room, because it also costs less to run the cooling system. See how to do this by reading the Trust’s Planning Guidelines for Server Rooms ("Projekteringsvejledning for serverrum") and the Trust’s Interior Layout Guidelines ("Indretningsvejledning 2008") (both in Danish).
- Factor energy consumption into purchasing policies. Electricity consumption accounts for a significant share of the total cost of running a server room. Therefore factor electricity consumption into purchasing policies for IT and cooling equipment.
- Try the Trust’s tool (in Danish) and get an initial overview of savings opportunities.
Further information
> Read more recommendations about server rooms.
> Find information on the EU Broadband Equipment Code of Conduct, UPS equipment and data centres at sunbird.jrc.it
Notes and further definitions: Servers
- "ENERGY Star Version 1.0 Program Requirements for Computer Servers" provides a full description of the scope and definitions.
- Servers which do not meet the criteria:
- Blade systems including blade servers and blade chassis
- Fault tolerant servers.
- Server appliances.
- Multi-node servers (more than 2 independent servers)
- Storage equipment including blade storage.
- Network equipment.
- Servers with greater than 2 processor sockets must reduce power during times of low utilization. See Energy Star for servers version 1.0 for further definitions.
- A managed server is understood to mean a server designed for a high level of availability in a highly managed environment. A managed server must have the following characteristics:
- Capability to operate with redundant power supplies.
- An installed management controller (e.g. service processor)
- A multi-output power supply (AC-DC & DC-DC) is understood to mean a power supply which delivers power at several voltage levels.
- A single-output power supply (AC-DC & DC-DC) is understood to mean a power supply which delivers power at one voltage level.
Notes and further definitions: Uninterruptible Power Systems (UPS)
- Description of scope and definitions.
- See Table below for energy efficiency for other levels (25%, 50% og 75%).
| UPS power mode | For UPS double conversion in basic configuration (VFI-S) | For all VI and VFI UPS (except VFI-S) | For all VFD UPS |
| 10 ≤ UPS-power < 20 kVA | |||
| - 25 % of nominel power | 83% | 88% | 93% |
| - 50 % of nominel power | 89% | 92% | 95% |
| - 75 % of nominel power | 90.5% | 92.5% | 95.7% |
| 20 ≤ UPS-power <40 kVA | |||
| - 25 % of nominel power | 84% | 88.5% | 93.5% |
| - 50 % of nominel power | 89.5% | 92.5% | 95.5% |
| - 75 % of nominel power | 91% | 93 % | 96.3% |
| 40 ≤ UPS-power < 200 kVA | |||
| - 25 % of nominel power | 86.5% | 89% | 94% |
| - 50 % of nominel power | 90.5% | 93% | 96% |
| - 75 % of nominel power | 92% | 93.5% | 96.7% |
| 200 kVA ≤ UPS-power | |||
| - 25 % of nominel power | 89% | 91.5% | 95% |
| - 50 % of nominel power | 92% | 94.5% | 97% |
| - 75 % of nominel power | 93% | 94.5% | 97.7% |
- Additional isolation transformers are permitted additional loss of between 0.5% and 3.6% depending on the UPS power mode and the load on the transformer. Additional losses are shown in the Table below. Measurements should be made in accordance with EN 62040-3, Annex AA.
| Share of nominal power | Permitted additional loss per transformer | Permitted additional loss per transformer | Permitted additional loss per transformer | Permitted additional loss per transformer |
| 10 ≤ power < 40kVA | 40 ≤ power < 200 kVA | 200 ≤ power < 500 kVA | 500 ≤ power | |
| 25 % of nominal transformer power | 1.50% | 1.00% | 0.70% | 0.50% |
| 50 % of nominal transformer power | 1.90% | 1.50% | 1.10% | 0.70% |
| 75 % of nominal transformer power | 2.60% | 2.00% | 1.70% | 1.30% |
| 100 % of nominal transformer power | 3.60% | 3.20% | 2.70% | 2.00% |
- When using additional device to reach harmonic currents at the input better than defined in IEC 61000-2-2, 61000-3-2 and 61000-3-12, losses for this equipment (per device) of between 0.6% and 2.5% are permitted depending on load, with maximum loss allowable at 100% of nominal power. Permitted losses are shown in the Table below.
| Share of nominal power | Maximum loss |
| 25% of nominal transformer power | 0.60% |
| 50% of nominal transformer power | 1.00% |
| 75% of nominal transformer power | 1.60% |
| 100% of nominal transformer power | 2.50% |
- For measurement methods see EN 62040-3 ed. 1.0 b:1999.
Notes and further definitions: Small-scale servers
- "ENERGY STAR Program Requirements for Computers: Version 5.0" provides a full description of the scope and definitions.
- Wake On Lan (WOL): Functionality which allows a computer to wake from Sleep or Off when directed by a network request via Ethernet.
- Idle: The state in which the operating system and other software have completed loading, a user profile has been created, the machine is not asleep, and activity is limited to those basic applications that the system starts by default.
- Read more about configuring a monitor via the computer.
Notes and further definitions: Network and broadband equipment
- Description of full scope and definitions.
- Low power state means a state in which the device is not processing or transmitting a significant amount of traffic, but is ready to detect activity.
- Additional consumption is permitted with additional functionality. See EU Code of Conduct - Version 3, 18 November 2008 (pages 14-19).
- See EU Code of Conduct - Version 3, 18 November 2008 (page 27) for definitions of terms.
Page last updated 23.11.2010