ATX Version 3.0 Multi Rail Desktop Platform Power Supply
Design Guide
Power Supply Efficiency for Energy Regulations - ENERGY STAR* and CEC (California Energy Commission) PC Computers with High Expandability Score - RECOMMENDED
The efficiency of the power supply should be tested at nominal input voltage of 115 VAC input and 230 VAC input, under the load conditions defined in the form factor specific sections, and under the temperature and operating conditions defined in Chapter Chapter 7. The loading condition for testing efficiency represents fully loaded systems, typical (50%) loaded systems, and light (20%) loaded systems. For systems being sold into the state of California that meet the High Expandability Computer definition (details at the referenced CEC website below) are required to meet the efficiency target list in Table 4-16: Efficiency versus Load for CEC PC Computers with High Expandability Computers*7.
Visit ENERGY STAR* Computers Ver.8 (ES v8) website for more details:
Visit CEC* website for more details:
- https://www.energy.ca.gov/rules-and-regulations/appliance-efficiency-regulations-title-20 or
- https://energycodeace.com/content/reference-ace-t20-tool then select section “(v) Computers…”
Table 4-15: Efficiency versus Load for ENERGY STAR*
Loading | Full Load (100%) | Typical Load (50%) | Light Load (20%) | PFC @ 50% load | Remarks |
RECOMMENDED Minimum Efficiency | 82% | 85% | 82% | ≥0.9 | ES v8 for 500W and below |
RECOMMENDED Minimum Efficiency | 87% | 90% | 87% | ≥0.9 | ES v8 for above 500W |
Table 4-16: Efficiency versus Load for CEC PC Computers with High Expandability Computers*
Loading | Full Load (100%) | Typical Load (50%) | Light Load (20%) | PFC @ 50% load |
REQUIRED Minimum Efficiency for 115V PSU | 87% | 90% | 87% | ≥0.9 |
REQUIRED Minimum Efficiency for 230V PSU | 88% | 92% | 88% | ≥0.9 |
*Details about High Expandability Computers definition check CEC computer regulation.
The RECOMMENDED minimum efficiency levels shown in Table 4-15 are required for internal power supplies within the ENERGY STAR* for Computers Version 8.0 specification.