What Is a 24-Pin Power Supply?

Power supply specification ATX specification is a motherboard and power supply structure standard developed by Intel Corporation in 1995. ATX is an abbreviation of English (AT Extend). The ATX power specification has gone through stages such as ATX 1.1, ATX 2.0, ATX 2.01, ATX 2.02, ATX 2.03, and ATX 12V series. ^[1]

Power Specifications

Starting from P4, the power specification starts to use ATX 12V 1.0 version. Its main difference from ATX 2.03 is to use + 12V voltage to power the CPU instead of using the previous + 5V voltage. This strengthens the + 12V output voltage and will achieve a much higher load than the + 5V voltage, thereby solving the high power consumption problem of the P4 processor. The most noticeable change is that for the first time, a separate 4Pin power supply interface has been added to the CPU, and the + 4V output voltage is used to separately supply power to the P4 processor. In addition, the ATX 12V 1.0 specification also makes corresponding provisions on the peak surge current, the capacity of the filter capacitor, and the protection circuit to ensure the stability of the power supply. In April 2003, Intel released the new ATX 12V 1.3 specification. In addition to strengthening the + 12V output capability of the power supply again, in order to ensure the safety of the output line and avoid losses, the new specification has deliberately established a limit of a single + 12V output not exceeding 240VA. Considering the need for environmental protection and energy saving, the ATX 12V 1.3 specification also stipulates that the full-load conversion efficiency of the power supply must reach more than 68%, which requires power supply manufacturers to implement PFC circuits. At the same time, the new specification also provided a dedicated power supply interface for the emerging SATA hard drives at the time.

In 2005, with the advent of PCI-Express, which drove the demand for power supply for graphics cards, Intel introduced the power supply ATX 12V 2.0 specification. This time, Intel chose to add a second + 12V output to solve the power supply problem of high-power devices. The power supply will use dual + 12V outputs, of which one + 12V still provides a dedicated power supply output for the CPU. The other + 12V output powers the motherboard and PCI-E graphics card to meet the needs of high-performance PCI-E graphics cards. Due to the use of dual + 12V outputs, the main power interface connected to the motherboard has also been increased from the original 20-pin to 24-pin, which are respectively composed of a 12 × 2 main power supply and a 2 × 2 dedicated CPU power interface. Although the interfaces are connected together, the two + 12V power supplies are completely separated on the wiring and output independently. Such a higher version of the power supply can divide the main power supply 24 pin into 20 + 4 two parts, compatible with the old motherboard using the 20-pin main power connector. In addition, the ATX 12V 2.0 specification also raises the standard for full-load power conversion efficiency to more than 80%, further meeting the requirements of environmental protection and energy saving, and once again strengthening the + 12V current output capability. After formulating the ATX 12V 2.0 specification, Intel also made small revisions of ATX 12V 2.01, ATX 12V 2.03 and other versions on the basis of it, which mainly increased the current output requirement of + 5VSB. Since May 2006, Intel has introduced the ATX 12V 2.2 specification. In contrast, the new version has not changed much, mainly to further increase the maximum power supply.

When choosing a power supply, you should try to choose a higher specification version of the power supply. First of all, the high-standard version of the power supply is fully backward compatible. Secondly, the new standard 12V, 5V, 3.3V output power distribution is usually more suitable for the power requirements of current computer accessories. For example, the ATX 12V 2.0 specification allocates more power to the 12V output even when the total power is the same. With 3.3V and 5V power output, it is more suitable for the needs of the latest computer accessories. In addition, the high-specification version of the power supply directly provides the power interface required by the motherboard, graphics card, hard disk and other hardware without additional conversion. Of course, there are exceptions, such as an old system, and it happens that the power requirements of 3.3V and 5V are very high, then you may need to buy the power supply of the old specification. ^[1]

A masterpiece of dual output-ATX12V 2.0 standard

2005 is the fastest year for PC hardware transformation and speed-up. Among them, the graphics card interface that users pay most attention to has been upgraded from AGP 8 × to PCI-E × 16. After the release of the new standard, Ati and nVIDIA followed the pace of Intel to launch high-performance PCI-E × 16 interface graphics cards. Multiple pipelines and large video memory for a while became a topic of interest for DIY players. However, while users enjoy high-performance hardware, problems such as high power consumption and high heat generation also follow. Players who upgraded with the old power supply began to encounter "nightmare" level failures such as blue screens, freezes, and restarts. The reason is that these are caused by insufficient power supply. For this reason, with the successive listing of PCI-E interface motherboards, Intel officially launched the ATX12V 2.0 power supply standard.

The ATX12V 2.0 standard is a type of ATX power specification. Essentially, the ATX12V 2.0 standard was developed to address the issue of rapid "bloating" of CPU power consumption. Compared with the ATX12V 1.3 standard, the most obvious improvement of the ATX12V 2.0 standard is the dual + 12V output design. + 12V1DC supplies power to the motherboard and PCI-E × 16 graphics card through the main power interface (12 × 2) to meet the current required for stable operation of the graphics card and DDR2 memory; while + 12V2DC supplies power to the CPU exclusively through the (2 × 2) interface. In the motherboard wiring, + 12V1DC and + 12V2DC are also completely separated, and the main power interface is also changed from the original 20Pin to 24Pin output.

In addition, another important improvement of the ATX12V 2.0 standard is increased conversion efficiency. Conversion efficiency is the ratio of output power to input power. The ATX12V 1.3 standard specifies a minimum conversion efficiency of 68% at full load, and the 2.0 standard increases the conversion efficiency to 80%, making full use of energy. Don't underestimate the parameter of conversion efficiency. In addition to the increase in the value, in addition to making the power supply products more environmentally friendly and saving electricity, the proportion of residual electricity converted into heat is also small. That is to say, the heat generated by ATX12V 2.0 standard power supply per unit of operation time is smaller than that of ATX12V 1.3 standard power supply, which has a critical impact on power supply heat dissipation and component life.

During the vigorous development of the ATX12V 2.0 standard, Intel "planned" four power specifications in total, namely ATX12V 2.0 standard 250W, ATX12V 2.0 standard 300W, ATX12V 2.0 standard 350W, and ATX12V 2.0 standard 400W. These four levels of standards stipulate + 12VDC The output must reach 22A.

Although it has been more than two years since the announcement of the standard, 10% of ATX2.0 and even ATX1.3 standard power supplies are still on the market. The products are basically concentrated in the price of tens of yuan-300 yuan, and the power of 200W-300W. These power supplies are suitable for single-core processors and integrated motherboards to form entry-level entertainment and dormitory platforms, which are affordable and have sufficient performance. In addition, users installed before 2006 had the same power supply at that time, and the power did not exceed 300W. Therefore, when upgrading the system, it is not a big problem to choose hardware such as single-core CPU and 7300GT. However, if dual-core CPU, 7900GS and other products are used, the system will be overwhelmed due to the surge in power consumption.

Support dual-core green environmental protection-ATX12V 2.2 standard

In early 2006, Intel significantly reduced the price of its entry-level model of its PentiumD dual-core processor, and a dual-core popularity storm that "bred" for half a year has officially begun. At the same time, Intel once again updated its "proud" ATX12V power standard, and the new ATX12V 2.2 standard fully optimized the dual-core processor.

Compared with the ATX12V 2.0 standard released in 2005, the ATX12V 2.2 standard has new requirements in terms of maximum output power, current characteristics of each channel, and conversion efficiency.

In order to adapt to the rapid increase of CPU core frequency, graphics performance, memory, hard disk capacity and other aspects of the dual-core platform, Intel added the 450W output specification to the ATX12V 2.2 standard and provided a load cross diagram for reference. In this way, for users using a dual-core SLI platform, even if a 7900GS-grade graphics card is used for dual-card interconnection, a 450W rated power supply is sufficient.

In terms of current output characteristics, the new 2.2 standard does not increase the current sustainability of + 12V, but instead decreases it, but greatly improves the instantaneous output capability of + 12V. The reason why there will be such changes in the new standard is that Intel considers that with the continuous improvement of process technology, the mainstream dual-core and even multi-core processors in the future may not maintain an increase in overall power consumption, but these processors need to be higher at the moment of startup. Power supply. Therefore, in order for the system to run stably, it is necessary to increase the current peak value of + 12V output. In addition, the 2.2 standard increases the output current of 3.3V and 5V to meet the power supply requirements of SATA hard drives and optical drive devices with increasing occupancy.

In terms of conversion efficiency, the new ATX12V 2.2 standard still requires a conversion efficiency of 80%, and it is more in place than the 2.0 standard in terms of implementation. In the United States in 2006, some organizations (including Intel) have required computer manufacturers to adopt ATX12V 2.2 standard power products with energy conversion efficiency of 80%. As a "return", they will provide rebates and other preferential policies on channel policies to achieve the "long-term" purpose of increasing the output of green energy-saving computers.

ATX2.2 standard power supply is a necessary configuration for purchasing dual-core hosts now. Generally, products of 350W-400W grade can easily deal with mid-to-high-end gaming platforms such as Core 2 + X1950Pro, which provides a "power" foundation for system overclocking. Because the default power of the ATX2.2 standard is relatively high, if you choose 400W and above products, even if it can cope with a "next-generation" configuration such as a high-frequency dual-core processor + G8600GTS, it is completely feasible. So if you choose to install ATX2.2 standard power supply, you will not "regret" choosing a product with higher power.

High and low with no worry-ATX12V 2.3 standard

On April 3, 2007, Intel released the latest ATX12V 2.3 standard, and the power specification that was "quiet" for a year was upgraded again. The 2.3 standard released by Intel this time is mainly aimed at the hardware upgrade brought by Vista system and the power consumption changes of dual-core and multi-core processors.

At present, due to the continuous improvement of integrated chipset performance, many low-end users no longer use the purchase of independent graphics cards as a necessary choice for the first installation. Therefore, it is somewhat "big and small" to buy dual-channel power products. This time Intel introduced a single + 12V power supply standard with three power levels of 180W, 220W and 270W in the ATX12V 2.3 standard, providing an economical product solution for entry-level users.

In addition, in terms of high-power power supply, the 300W, 350W, 400W, and 450W power levels given by the ATX12V 2.3 standard are all born to support high-end Vista graphics cards. And compared to the 2.2 standard, the + 12V1 output capacity in the 2.3 standard has been improved, and the + 12V2 output capacity has decreased, which directly reflects the "stark" contrast between the continuous increase in power consumption of graphics cards and the continuous decline in CPU power consumption.

In 2007, the ATX2.3 standard power supply has not yet been listed in batches, and there are only a few models of "grabbing and landing". Therefore, it is recommended that users who want to buy be "holding coins for purchase" for a period of time. Because the ATX2.3 standard is optimized on the dual + 12V output compared to the ATX2.2 standard, it is "tailored" for the next stage of CPU, graphics and other accessories, which can better "appetite" these new high-end products. Therefore, I suggest that if you want to match a set of entertainment hosts with good upgrade potential, purchasing ATX2.3 standard power supply will maximize the life of the platform.

In addition, since the ATX2.3 standard has re-planned the single + 12V output power supply specification, this type of product is definitely more competitive in price. The use of "hand-to-hand" with single-core CPU + integrated motherboard is undoubtedly the entry-level in the next stage. A wise choice for users to install.

ATX12V 2.31 standard

ATX12V version 2.31 specification In terms of facts, it is only a supplement and improvement to the ATX12V version 2.3 specification. Specific improvements include:

1) Remove the PW-OK signal from the ATX12V version 2.3 specification and add it back to the ATX12V version 2.31. After many internal tests at Intel, it was found that removing the PW-OK signal will cause the DC output time to be prolonged, thereby increasing power loss.

2) Make a series of adjustments to the interleaved load of CFX12V. This adjustment is for almost all ATX12V specifications. Intel has further made a series of adjustments to the interleaved load of CFX12V. The minimum load adjustment is the most prominent. Through the modified adjustment, the cross-load adjustment rate has been improved. And through the optimization of cross adjustment, so that the output voltage of the power supply is more stable. This also indicates that users can more freely match the CPU and graphics card without worrying about compatibility or instability issues.

3) Increased RoHS environmental protection standards and promoted to the highest position. The RoHS-2002 environmental protection standard ("Direction on Prohibition of the Use of Certain Hazardous Substances in Electronic and Electrical Equipment") was officially promulgated by the European Parliament and the Council of the European Union on January 27, 2003, stipulating that lead Pb and cadmium Cd in electrical equipment , Mercury Hg, hexavalent chromium Cr6 +, polybrominated diphenyl ether PBDE, polybrominated biphenyl PBB and other content restrictions. It can also be seen from this point that Intel has joined the action plan to protect the global environment and save the global climate.

4) More stringent requirements improve conversion efficiency. This is also Intel's continuous efforts to fulfill its advocated energy-saving and environmental protection plan. At the same time, it also accepted the Chinese 3C compulsory certification requirements for EMI circuits. While ensuring continuous improvement of energy saving effects, it also brings higher stability.

In view of the above, the ATX12V version 2.3 specification is more in line with the mainstream needs of today, and it is significantly different from the previous power supply specifications. The ATX12V version 2.31 specification is more in line with today's mainstream applications, and it is efficient, environmentally friendly and energy efficient. The design is also more complete. Therefore, we have reason to believe that ATX12V version 2.31 power supply will enter the mainstream market and eventually become popular. Unless the main component power consumption changes.

The main output interface of the power supply refers to the power supply interfaces that the power supply provides to the motherboard, graphics card, hard disk, optical drive, and floppy drive.

The first is the main power supply interface on the motherboard. Previously, the main power supply interface on the motherboard was 20-pin.

Since the ATX 12V 2.0 specification, many motherboards have begun to use a 24-pin main power supply interface. Obviously it is more appropriate to buy a power supply with a 24-pin main power supply interface. Of course, in order to solve the problem of backward compatibility, most of the main power supply interfaces of 2.0 power supplies adopt a separate design or a 24Pin 20Pin conversion connector is provided, which is very considerate in design.

In addition, 80% of computers now use SATA hard disks, but the old hard disks and most optical drives are still traditional "D" type power supply interfaces. No need to add adapters.

In addition to the main power supply interface, many motherboards may also require 4-pin or even 8-pin independent power supply interfaces, which are usually used to provide auxiliary power for the CPU. And some high-power consumption PCI-Express graphics cards may also require a 6-pin auxiliary power supply interface. If it is a computer with two graphics cards, it may require two 6-pin auxiliary power supply interfaces.

When purchasing a power supply, it is obvious that the richer the interfaces, the better, so that it will be convenient when connecting various hardware, and it will not be impossible to connect or the number of interfaces is not enough. If you can't determine which interfaces the power supply has before purchasing, it is recommended to choose a power supply that meets the higher power supply specifications. For example, the newer specification is ATX 12V 2.2 version. The power supply of the higher specification version usually has richer power supply interfaces. In addition, if there is a lack of power interface, you can also get some missing interfaces by buying some adapters, of course, provided that the power supply of the power supply is sufficient.