Power Supply Testing Methodology
at EXTREME Overclocking
Date Published: June 2, 2005
Author: Jason Rabel |
Different ATX12V Specifications:
There are three main revisions of the ATX12V guidelines that PSU manufacturers tend to follow these days. Any power supply that only has one (1) 12V rail automatically falls into the v1.3 specs. A power supply with two (2) or more 12V rails will fall under one of the 2.x specification.
| ATX12V Specification Differences |
| |
v2.2 / v2.1 |
v2.01 / v2.0 |
v1.3 |
| Main Power Connector |
2x12 |
2x12 |
2x10 |
| 12V Rails |
Two |
Two |
One |
| SATA Connector |
Required |
Required |
Optional |
Min Req Efficiency
(Typical Load) |
72% |
70% |
60% |
| Power Emphasis |
12V |
12V |
5V |
One extremely important thing to note is the ATX12V Power Supply Design Guide is exactly that, simply a "guide". Here's a paragraph taken from the beginning of the ATX12V document, stating in better detail their intentions.
This document is provided as a convenience only and is not intended to replace the user’s independent design and validation activity. It should not be inferred that all ATX12V power supplies must conform exactly to the content of this document. The design specifics described herein are not intended to support all possible system configurations. System power supply needs vary widely depending on factors such as the application (that is, for desktop, workstation, or server), intended ambient environment (temperature, line voltage), or motherboard power requirements.
There are certain requirements however for a power supply to say that it meets a certain spec, and are clearly stated in the document. Things such as specific connectors, minimum efficiency levels, split 12V rails, various safety features, and much more, are all required. Details such as internal design, power distribution, and other technicalities, are left up to the manufacturer to determine what is the best for their target market.
The table below illustrates an important point differentiating v2.x to v1.3 specifications, two power supplies with the same overall power rating have two completely different power distributions. I looked up these specs online from two different reputable manufacturers, so these are real numbers. People shouldn't think they are being tricked or cheated when they buy a power supply conforming to v1.3 specs, they have to realize the power supply was designed for systems that used the 5V rail for primary power.
| ATX12V Power Supply Differences |
| Voltage Rail |
v2.01 |
v1.3 |
| 3.3V |
32A |
35A |
| 5V |
40A |
50A |
| 12V1 |
19A |
30A |
| 12V2 |
19A |
- |
| Total Output |
550W |
550W |
In recent times we have seen a sharp move away from the 5V rail, and instead motherboard & video card manufacturers are using the 12V rail to meet their high-current demands. Thus the v2.x specifications reflect this change to accommodate the different levels of power required.
Different Power Supply Manufacturers:
Not every company that sells power supplies actually makes them in-house. Most of the time a different company (which you may or may not have heard of) is the OEM supplier which produces near-identical power supplies for several companies at a time. To determine who actually "made" the power supply is a simple enough task. If you look at the label on the side of your power supply, there is a number printed below the UL logo (ex: E161451). You can lookup the UL File Number online at the UL website telling you who that file number is registered to (and thus who made the power supply).
Here's a list of some of the more popular PSU makers:
- E104405 Sea Sonic Electronics Co Ltd
- E104407 Leadman Electronics Co Ltd
- E119368 Samsung Electro-Mechanics Co Ltd
- E126556 Taiwan Youngyear Electronics Co Ltd
- E130843 Topower Computer Industrial Co Ltd
- E131500 Pc Power & Cooling Inc
- E131881 Delta Electronics Inc
- E134014 Enermax Technology Corp
- E134129 Powertech Systems Co Ltd
- E138711 Moretec Electronics Industrial Co Ltd
- E141182 Morex Information Enterprise Co Ltd
- E141400 Seventeam Electronics Co Ltd
- E142789 Nidec Potrans Corp
- E143709 Hipro Electronics Co Ltd
- E143756 Zippy Technology Corp
- E144195 Sirtec International Co Ltd
- E147055 Mapower Electronics Co Ltd
- E156513 Power-Win Technology Corp
- E161451 Channel Well Technology Co Ltd
- E161557 Fortrex Electronic Co Ltd
- E161936 Nipron Co Ltd
- E164554 L & C Technology Inc
- E166947 Enhance Electronics Co Ltd
- E172499 Win-Tact Electronics Corp
- E175472 Fore Point Industrial Ltd
- E175856 Delta Electronics Inc
- E176105 Antec Inc
- E176239 Etasis Inc
- E178102 Jou Jye Electronic Co Ltd
- E178768 Wintech Electronics Corp
- E181356 Shenzhen Chi Yuan Industrial Co Ltd
- E185650 King Case Industrial Co Ltd
- E186010 Atng Power Co Ltd
- E190414 Fsp Group Inc
- E191395 Delta Electronics (Thailand) Public Co Ltd
- E193726 Ablecom Technology Inc
- E193807 Powertech Systems Co Ltd
- E199068 Delta Electronics Inc
- E199442 Heroichi Electronic Co Ltd
- E199529 Macron Power Technology Ltd
- E203196 Deer Computer Co Ltd
- E211481 Codegen Technology Co Ltd
- E217431 Delta Electronics Inc
- E243823 OCZ Technology
- E313881 Delta Electronics Inc
|
eWeek is the essential technology information source for builders of e-business. Focuses on e-commerce, communications and Internet-based architecture.
Oracle Magazine contains technology-strategy articles, sample code, tips, Oracle and partner news, how-to articles for developers and DBAs, and more.
Dr. Dobb's Journal enables programmers to write the most efficient and sophisticated programs and help in daily programming quandaries.
InformationWeek is the only newsweekly you'll need to stay on top of the latest developments in information technology.