Computer power source: More important than you think

When building a new computer system, users often don't pay attention to a very important component - the power supply. Often people spend quite a bit on the main components of the computer such as CPU, RAM, motherboard . Spending $ 150 for the new generation graphics card seems more reasonable than investing the money for the power supply ( BN) or Power Supply Unit (PSU). However, the tests show that the power supply plays an important role in the performance of the system . Dual-core, dual-graphics chips and other terrible power-hungry toys are increasingly putting pressure on the power supply. This article introduces the basic concepts, important parameters, ways to identify a good and suitable source for your computer.

The basics of computer power supplies

All types of power supplies when shipped must have quality certification stamps with sufficient parameters such as voltage, capacity .

1. Capacity

Computer power source: More important than you think Picture 1

Power capacity, value is calculated as follows:

Watt (W) = Voltage (V) x Ampere (A);

where V is the voltage, and A is the electric current .

2. Electric lines

Power supplies often have many different power lines, including: + 3.3V, + 5V, + 12V, -5V, -12V . Their meanings are as follows:

1. 12V : Used mainly for Serial port circuits and is rarely used on new systems. Although new power supplies are backward compatible, the capacity of -12V lines is less than 1A.
2. 5V : Mainly used for floppy drive controllers and power supply circuits for old ISA slots. Line capacity -5V is also below 1A.
3. 0V : This is the "cool" (Ground) line of personal computer systems.
4. 3.3V : As one of the new voltage levels on modern power supplies, it appeared for the first time when the ATX standard was born and was originally used primarily for microprocessors. Currently, new motherboards (BMCs) line up + 3,3V lines to feed main memory.
5. 5V : The main task is to power BMC and peripheral components. In addition, microprocessors like Pentium III or AthlonXP also get power from the 5V line through the current step. On new systems, the majority of component components gradually shift to use 3.3V lines except CPU and BMC.
6. 12V : In modern computer systems, this is the power line that plays the most important role, originally it was used to power the motor of hard disk as well as the power fan and some other cooling devices. Later, the new design allows for system slots, expansion cards and even CPUs to "follow" the + 12V line.

When the power switch is pressed for the first time and the power supply starts up, it will take a while for the components in the output power to power the active computer components. Before that, if the computer starts, the components will be damaged or not working properly due to unstable power lines. So on new systems, sometimes it takes 1-2 seconds after you press the machine switch button to start working the system. This is because the system must wait for a green light signal to indicate that the voltage is ready from the power supply to the BMC. Without this signal, BMC will not allow the computer to function.

Among the main electric lines, lines with positive values ​​(+) play a more important role and you must keep an eye on them. Each line will have its own Ampere (A) indicator and the higher the number, the better. The total power is calculated by the formula W = VxA. For example, the power supply has a 3.3V line of 30A, 5V is 30A and 12V is 25A, the power lines and capacity are calculated as follows:

1. Power line capacity 3.3V = 3.3V x 30A = 100W
2. Power line capacity 5V = 5V x 30A = 150W
3. Power line capacity 12V = 12V x 25A = 300W

So the total power capacity will be 100W + 150W + 300W = 550W. However, in fact, there are many other factors that affect this total number and we will mention later in this article.

3. Standard of power supply

The current dominant desktop standard is the ATX (Advanced Technology Extended) 12V, designed by Intel in 1995 and has quickly replaced the old AT standard with many outstanding advantages. If with the AT source, activating the on mode is done via a switch with four electrical contacts, with the ATX power supply you can turn it on or off with the software or just connect the two-pin plug (green wire). leaves and one of the Black Ground wires). Standard ATX sources always have a total switch that can completely disconnect the current from the computer. ATX has 5 main design branches:

Computer power source: More important than you think Picture 2

1. ATX: 20-pin main jack (usually for Pentium III or Athlon XP).
2. WTX: 24-pin main jack, used for Pentium II, III Xeon and Athlon MP.
3. ATX 12V: 20-pin main jack, 12v 4-pin auxiliary jack (Pentium 4 or Athlon 64).
4. EPS12V: 24-pin main jack, 8-pin auxiliary jack for Xeon or Opteron systems.
5. ATX12V 2.0: 24-pin main jack, 4-pin auxiliary jack (Pentium 4 775 and Athlon 64 PCI-Express systems)

Recently, a new standard, called BTX (Balanced Technology Extended), has a different arrangement of internal components than the current ATX, allowing system developers more options to solve problems. heat and noise . BTX is optimized for new technologies such as SATA, USB 2.0 and PCI Express. The heat treatment factor in BTX computers is greatly improved: most of the main radiant components are placed in the main wind flow, so it will avoid having to add their own fans (will cause more energy , increasing noise and cramped unnecessarily). Currently you can find some power supplies with certification stamps that support BTX but not much because they are not common.

4. Types of plug pins

Computer power source: More important than you think Picture 3 The power cord for computer power is very color coded, red is + 5v, yellow is + 12v, black is "cool" (Ground) . They are grouped into legs The following basic plug:

- Molex : Used for all kinds of hard disks and optical drives, you can also use them to plug in fans and some other devices such as AGP graphics cards (GeForce 5, 6 or Radeon X800) or BMC like Asus or DFI.

- Main power plug : Original ATX originally had 20 pins, standard 2.0 raised the number of main pins to 24 feet. You can also find a number of power pins with 20 + 4 pins with mounting pins for use on both BMCs with 20 or 24-pin power connectors.

- 12V auxiliary wire : Appears with the Pentium 4 system. This line consists of 4 plugs with 2 12V pins and 2 "cool" pins.

- SATA connectors : The latest power supplies must have a minimum of 2 to 4 flat pins for modern SATA hard disks. However, you can also use wire segments if your source doesn't have this type of pin.

- PCI-Express heads : Similar to SATA pins, PCI-Express connectors are indispensable in new generation power supplies. Power sources with SLI or Crossfire certification for dual graphics systems always have up to two connectors of this type for use with PCI-Express graphics cards. Of course, if your source does not have a plug and still wants to use a new graphics card, you can still use conversion jacks (sometimes with a card).

- Floppy drive plug : Originally, this jack was used for floppy drives, it also included 2 ground wires, 1 + 5V wire and 1 + 12V cable. Later, there are many other devices that use this type of plug-in as graphics cards, ATA-SATA converters of hard disks and even BMC like DFI Lanparty NF4.

- 8-pin EPS plug : Commonly used for workstation motherboards on professional computer systems with CPU Opteron or Xeon. Recently, some new BMC desktops also started using this plug, such as Asus' P5WD2 line.

Currently, the Modular Concept of the computer power supply is starting to be used. Try imagining an ATX 2.01 standard power supply that will have 8-10 Molex plugs, 1 main plug, one or two PCI-Express connectors, 1 12V head, 2 to 4 SATA terminals and some terminals. Other special specials. However, if your computer system is only at the basic level and uses less than half of these plugs, it is quite troublesome to neatly arrange the extra plugs inside the machine. Modular Concept allows you to plug only wires with the required connectors and remove unnecessary pins. So your interior case will be neat and facilitate general cooling solutions. However, this new design is currently only available on expensive high-end power supplies.

5. Negative power lines

If you use some electrical measurement software or even a meter, you will find that the values ​​of the negative line (-) are quite low compared to the positive lines (+). This is because they are no longer important now. Although a 20-foot ATX power supply has a 12-pin pin -12v and a pin number 18 -5v, it is almost never used. Some devices require negative voltages including:

1. ISA expansion cards.
2. Serial or LAN port
3. Old generation floppy drive.

6. Power maintenance time (Hold-up time)

The Holdup Time value determines the amount of time in milliseconds that a power supply can maintain at the rated power line when the power line is cut off (for example, a power failure). This is useful especially when you live in an unstable electrical area (for example, when the power is suddenly turned off and then again, the computer can still function normally). The Hold-up time value of the ATX standard is 17ms and the computer power supply should be as high as possible.

7. Power Factor Correction (PFC)

PFC allows for high power efficiency. There are two main types of PFCs: Active PFC and Passive PFC. All existing power supplies are in one of these two categories.

- Active PFC : This is the most effective type. It uses an automatic circuit that adjusts power efficiency to 95% (theoretically). In addition, the Active PFC also has the ability to suppress noise and align the power line (allowing you to plug in any 110V outlet for up to 220V common uses without having to worry about indicators). However, due to the complex architecture of Active PFC, the power supplies using this technology are quite expensive. Some Active PFC power supplies still allow users to use the switch to determine the input current.

- Passive PFC : This is the most common type today. Unlike Active PFC, Passive PFC aligns the current through the filter capacitors and therefore its ability to work will be changed over time as well as greatly influenced by external factors such as temperature, concussion . Power supplies using Passive PFC technology require users to reset the input voltage through a small switch. Passive PFC source is cheaper than Active PFC source.

All types of non-PFC sources (Non PFC) are currently not recommended. In some EU countries, all power supplies marketed are required to be equipped with or Active PFC or Passive PFC. PFC allows saving electricity, reducing the capacity of indoor power lines: this is very beneficial when you set up a computer room or use multiple machines with the same power. Active PFC power supplies often provide a more stable power line than Passive PFC, so the device in the machine is stable and has a longer life.

8. Maximum energy and continuous energy

Continuous Power (Continuous Power) refers to the power supply of the power source over a long period of time while the maximum power (Peak Power) indicates the maximum level in a short period of time. For example, if you plug a series of devices with a total capacity of around 430W into a 400-watt Continuous Power, they will still work for a short time if the Peak Power level of the source reaches over 430W but after a while certain time, the components in the source will malfunction.

9. Noise level

Computer power source: More important than you think Picture 4 The index that determines the noise level of a power supply is measured in single dB and it must be consistent with the noise level of the working environment. For example, in noisy office, the 30dB power supply may not be a problem but if in the family living room is quiet, this number will be uncomfortable, especially at night. An unspoken rule is that the power supply with 120mm fan will work more smoothly than the high-speed 80mm or 90mm fan power supply, although their cooling performance may be similar. When the power supply is working harder (raising many devices), the heat generated by it also increases and for power sources with fans to adjust the speed themselves, the number of fans is increased and the Noisy sounds began to appear. For example, when a power supply is working at 70%, the noise is only about 20dB but when it reaches 90%, the output volume will be up to 35dB or more. You should consider this issue carefully: if you need 300W power, you should choose 350W for an 85% working capacity, if you choose 400W, this number is only 75% and the noise level can be reduced accordingly.

Some ultra-quiet power supplies may not use fans or use very quiet fans, but most of them are not for normal computers because they are extremely expensive, typically like MGE's XG Magnum 500.

If you hang around on technology websites, you'll probably come across some power supplies with water-cooling solutions, but this is quite dangerous for less experienced people.

10. Voltage adjustment potentiometer (Adjustable Pot)

Some good power supplies come with small internal potentiometers to adjust the voltage for electric lines. In fact, if your 12V power line drops below 11.5V, it will cause instability for the entire system. Keep in mind that the ATX standard allows each voltage to oscillate around 5% and you can reset it to 12V via those potentiometers. However, this is an advanced feature and should only be done if you know what you are doing. Some source products completely convert these potentiometers out so that users can freely change themselves, such as Antec's TrueControl series.

The safety limit value of ATX standard electric lines is as follows:

No.

Power line

Gap

Minimum

Max

first

+ 5VDC

± 5%

+ 4.75V

+ 5.25V

2

+ 12VDC

± 5%

+ 11.40V

+ 12.60V

3

-5VDC

± 10%

-4.5V

-5.5V

4

-12VDC

± 10%

-10.8V

-13.2V

5

+ 3.3VDC

± 5%

+ 3.47V

+ 3.14V

6

+ 5V SB

± 5%

+ 4.75V

+ 5.25V

11. Soft Power mode and 5V standby signal

Soft Power is the way in which the power supply is turned on or off but instead of using the hard switch like the previous AT standard, it is activated when the BMC instructs the power supply. Thanks to this, users can control system power via software. You can easily verify this with the ability to shut down Windows operating systems or turn on the computer from the keyboard, mouse. The main principle for BMC to order the power supply is through the standby signal of the line + 5V Standby. This line is completely independent of the lines of other equipment and will signal whenever you plug in the power, some new BMCs usually have a signal light for status + 5V Standby. In addition, there are a few extra power lines on the computer system, including:

+ Touch line + 3.3V (+ 3.3V Sense) : The main function is to monitor the voltage of the + 3.3V line feeding BMC. As a result, the power supply can align the line for accuracy.

+ Fan control (Fan Control) : Fan control signals allow the system in general and BMC to specifically change the fan speed of the power supply. When the voltage of this current drops below 1V, the fan will automatically turn off. When the value is above 10.5V, the fan will operate at the maximum level. The main function of this design is to allow the system to turn off the fan when the computer is idle (Sleep Mode) or change the fan speed according to the component temperature.

+ Monitor fan status (Fan Monitor) : This is a companion of fan control feature, it allows monitoring fan rotation speed in the system. Its main task is to warn users when a cooling fan has a problem and stops working.

Computer power source: More important than you think Picture 5

Computer power source: More important than you think Picture 6

How to choose a good power supply for your computer

Are you planning to install a new computer set and are wondering what source to buy? Please refer to the following steps:

1. Calculate the 12V power line of the source

As you know, the 3 main power lines of a power supply are + 12V, + 5V and + 3.3V. Total capacity is calculated based on the intensity of each line. The sad fact, however, is that many computer power manufacturers often use tricks to increase the number of watts by "pushing" unimportant electrical lines (+ 5V and + 3.3V). Therefore, skip the watt figure and focus on the intensity of the 12V power line to determine the quality of a power supply. Ampere index of + 12V line can be found in the accompanying documentation or right on the product stamp (eg + 12V: 25A). Note that the new ATX12V 2.0 sources have up to 2 12V lines that allow separate load of power between the CPU and BMC (+ 12v1) independently from other components (+ 12v2). That allows more stable current. Some sources even have up to 3 different 12V lines such as RealPower 550W from CoolerMaster. Although this does not make sense for normal systems, when using super powerful computers for games or professional applications, there is a big difference.

2. Ensure accuracy

If you have just bought a power supply with only 10-20USD with a 28A sticker for + 12V line, it is definitely not correct. In the Vietnamese market today, there are many poor quality sources of origin are unclear, you can even buy an extremely high power source of up to 600W-700W for only 2/3 compared to the 350W power supply. branded goods, but that is not true capacity. That's not to mention the poor quality of power is often unstable after a long time of use and can damage some expensive components of the computer. In personal experience, usually BMC will be the first victim.

3. Consider capacity issues

You can get the power parameters of most devices from the product documentation or the manufacturer's website to calculate an approximate rating. The above two reference lines for power lines + 12V above will partly help you solve the problem. We have an example of a computer system as follows:

You can see that many devices use 2 or 3 power lines at the same time. For example, new graphics cards take power from both the AGP / PCI-Express expansion slot and the external 12V plug. With a relatively strong computer configuration, you will need about 350W of power. However, for safety purposes, we should calculate a little extra.

In fact, when building a computer system, users will have 2 cases:

a. Basic work:

Just calculate the correct power consumption of the components, rarely need to be much superior. Therefore, the source selection elements mainly focus on safety requirements and noise index. Normally, you can calculate the balance of about 10% -20% compared to the expected number of medium. In the above case you can choose 400W source is enough. Of course we mention real capacity, not just numbers on stamps. If you are planning to add decorative toys, fans or drives, you will need 450W of power with 12V lines of about 24A.

b. People who like to "play":

In this case, overclocking, lights, water radiators installed inside . will consume you a lot more energy. Computer components that run at higher speeds will naturally "consume" more power than the default. Usually you will need up to 45% more capacity and so the total power needed in the example above will be up to 145% x 350W = 507W. 12V power lines will have to reach a minimum of 18.84A x 145% = 27.3A.

Once we have found a suitable power supply and power + 12V, we must ensure the + 12V power architecture to meet the necessary equipment, for example the Pentium 4 3,4 Extreme chip. Edition needed 11A on the 12V road. If you use a power supply with two 12V - 14A lines, the safe range required for naughty overclocking will be narrower.

Computer power source: More important than you think Picture 7 Practically testing a system with the following configuration:

1. AMD Opteron DualCore 165 @ 2.9GHz.
2. DFI LanpartyUT nForce4 SLI-D.
3. nVIDIA GeForce 6800Ultra
4. 4x512 Corsair XMS PC3200C2.
5. 3x Maxtor Diamond Plus 9 120GB 7200rpm
6. DVD + DVD-RAM
7. Creative X-Fi Platinum
8. PCI Wifi Card
9. Toys: CoolerMaster Cooldrive6, Aerogate III, Aquamini / Hyper 6, Musketeer II, Cold Cathode lamps, 2 120mm LED fans and 4 80mm LED fans.
10. USB devices: Logitech G5 Mouse, G15 Keyboard, Momo Racing Wheels, Dinovo Media Desktop, card reader.

The results only stop at 180W when idle and nearly 300W when playing relatively heavy games like Halflife 2, Ages of Empire III or Quake 4.

Note, some manufacturers have unclear indexes, let's explore this issue in the following two small examples.

Computer power source: More important than you think Picture 8 The first source set has an index:
Output:

1. 3.3V rail = 30A
2. 5V rail = 40A
3. 12V rail = 34A

Continuous power = 510W max
Peak power = 650W max

We can calculate the capacity of electric lines as follows:

1. 3.3V: 100W
2. 5V: 200W
3. 12V: 408W

The second source set has an index:
output

1. 3.3V rail = 30A
2. 5V rail = 40A
3. 12V rail = 30A

Total power = 660W max
Measurements taken at 40F

Similar calculations as above, we have:

1. 3.3V: 100W
2. 5V: 200W
3. 12V: 360W

At first glance, it's hard to tell the difference between them. But pay close attention: on the second power supply stamp, the manufacturer's test temperature is only 40 degrees Fahrenheit, which is only about minus 4 degrees centigrade. about 38 degrees Celsius, equivalent to 100 degrees Fahrenheit, at this level on the theory that the second power supply can only provide constant constant current of less than 300W. Especially when the temperature reaches 70 degrees Celsius, this power supply even loses the ability to supply power to the system. The reality is not very often when the manufacturer tells you what temperature test power they conduct. High-class power supplies must ensure the ability to supply enough watts in conditions of 40-50 degrees Celsius.

Therefore, you should consider carefully when meeting a high-power source with very low prices. Quality is always proportional to cost, which is why you should choose products from reputable manufacturers. Always take care to read the parameters carefully and do not ignore any details. For example, Antec has 3 different types of 480W sources. TruePower version has 12V line up to 28A while TrueBlue only has 22A only. You should learn from your friends or online resources about the parameters of the source you are about to buy and read the product introduction before making a decision.

Ingredient

+ 3.3V

+ 5.0V

+ 12.0V

Athlon64 3500+

-

-

7.4 A

Common motherboard

3.0 A

2.0 A

0.3 A

Maxtor DM9 hard disk

-

0.9 A

0.7 A

Maxtor DM9 hard disk

-

0.9 A

0.7 A

RAID SATA Controller

2.0 A

0.5 A

-

nVIDIA GeForce 6800GT

0.1 A

3.94 A

3.02 A

nVIDIA GeForce 6800GT

0.1 A

3.94 A

3.02 A

2x 512 DDR400-

-

3.25 A

-

Audigy 2 ZS

0.5 A

0.5 A

-

2x120mm ventilation fan

-

-

0.6 A

Keyboard + USB mouse

-

0.5 A

-

DVD-RW

-

1.2 A

1.6 A

DVD-ROM

-

1.5 A

1.5 A

Total number of amps per line

5.7 A

22.13 A

18.84 A

Total watts

18.81 W

110.65 W

226.08 W

Total capacity

 

 

335.54 W

Some characteristics of various types of branded goods

Computer power source: More important than you think Picture 9 Famous manufacturers often launch a wide variety of products, rich in designs and features. Now you can find the following types of sources with attractive additional features:

- Load meter : This type of power supply will inform users about the total capacity of the system being used. Index levels are monitored continuously in real-time mode, so you can proceed with the upgrade when you find that the power supply is constantly overloaded.

- Separate fan wire : Some power supplies have 4-pin Molex wire with the symbol "Fan Only" for users to attach cooling fans to it. Usually these sources will also come with a potentiometer to adjust the Fan Only wire's voltage to change the fan rotation speed.

- Dây điện được bọc dạng tròn : Mỗi dây nguồn đều gồm nhiều sợi nhỏ nên sẽ khá vướng víu khi đưa vào bên trong case máy tính, vấn đề được giải quyết bằng cách bó gọn chúng trong ống lưới hay vỏ sợi kim loại chống nhiễu. Độc đáo hơn, một số dây nguồn còn có lớp bảo vệ UV, phát sáng khi bị tia cực tím chiếu vào.

- Lưới thoát nhiệt hình tổ ong : Với những bộ nguồn thoát nhiệt bằng quạt gió thông dụng, dạng lưới tổ ong sẽ cho phép luồng không khí đi qua dễ dàng, tăng mức giảm nhiệt, tăng công suất và tuổi thọ của thiết bị. Bạn cũng sẽ gặp các sản phẩm với lưới dạng tròn hoặc dạng dải, tuy nhiên hiệu năng kém hơn.

Computer power source: More important than you think Picture 10 - Fanless Design – SuperQuiet : Những nguồn với chứng nhận dạng này thường tập trung xử lý vấn đề tiếng ồn nhờ lớp vỏ nhôm. Bên trong là các khối tản nhiệt đồng cực lớn kèm theo hệ thống ống dẫn nhiệt heatpipe đồ sộ. Nhờ khả năng truyền tải nhiệt hiệu quả của các heatpipe (Xem thêm "Tản nhiệt kim loại – Lý thuyết và thực tế", ID: A0603_124) kèm theo những lá đồng nên các bộ nguồn loại này không cần tới quạt làm mát và tuyệt đối không phát sinh âm thanh nào trong khi hoạt động. Một số thử nghiệm của diễn đàn XtremeVN (xtremevn.com) trong điều kiện môi trường Việt Nam cho thấy nhiệt độ nguồn vẫn khá ổn định ở mức dưới 50 độ C khi hoạt động "hết mình".

- Modular Concept : Như đã đề cập ở trên, những bộ nguồn được thiết kế kiểu này cho phép tháo rời các dây cắm và chỉ sử dụng những sợi nào cần thiết để tiết kiệm diện tích vốn khá chật hẹp bên trong case.

- Tích hợp UPS : Một số bộ nguồn có tích hợp thành phần lưu điện UPS sẵn để hỗ trợ người dùng trong các tình huống mất điện bất chợt. Ưu điểm của các sản phẩm dạng này là bạn sẽ không cần phải mua thêm bộ lưu điện bên ngoài tuy nhiên khi ắc quy bị chai hoặc trục trặc sẽ rất khó thay thế.

- Khe điện phía sau : Việc đưa cổng molex ra phía sau của nguồn sẽ đem lại nhiều lợi ích hơn bạn tưởng. Những loại đèn trang trí, các ổ đĩa cứng gắn ngoài qua giao tiếp e-SATA thường thấy trên các BMC đời mới sẽ thực sự được hưởng lợi từ kiểu thiết kế này.

- Bộ nguồn đôi : Một số bộ nguồn hoặc case máy tính cao cấp thường tặng kèm người dùng một cáp chuyển cho phép cắm 2 bộ nguồn cùng nuôi máy tính để tăng công suất. Thiết kế này đòi hỏi bạn phải tự bố trí thêm khoảng trống cho bộ nguồn thứ hai.

Computer power source: More important than you think Picture 11
Bộ nguồn có chất lượng tốt

Computer power source: More important than you think Picture 12
Bộ nguồn kém chất lượng

Kiểm tra chất lượng dòng điện

Computer power source: More important than you think Picture 13 Có nhiều cách thức để kiểm tra dòng điện mà bộ nguồn cung cấp cho máy tính của bạn. Bộ nguồn tốt phải cung cấp được dòng điện "sạch" cho các linh kiện. Có nhiều người cho rằng các đường điện càng cao sẽ càng tốt nhưng thực tế điều này không đúng. Vấn đề ổn định dòng điện phải được đặt lên hàng đầu. Thao tác căn chỉnh các đường điện lên thật cao để khi hệ thống tải nặng chúng tụt xuống mức vừa đúng là chuyện lợi bất cập hại. Để theo dõi đường điện của bộ nguồn mới mua, bạn có thể sử dụng một số phần mềm chuyên dụng như Speedfan (almico.com) với chức năng lập biểu đồ theo thời gian.

Tất nhiên, giá trị cụ thể của các dòng điện do chương trình đưa ra chỉ mang tính tham khảo. Để có con số chính xác, bạn nên sử dụng các thiết bị đo chuyên dụng.

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Chuẩn ATX 1.3 và 2.x

Hiện có 2 chuẩn ATX phổ biến là chuẩn 1.3 và chuẩn 2.x .

ATXV1.3 chỉ có 1 đường (rail) 12V và có thể có hoặc không có đầu cấp nguồn SATA, thường thì các bộ nguồn chuẩn ATX V1.3 có hiệu suất thấp – chỉ đạt khoảng 60% - và có đường điện chính là đường 5V (thích hợp cho những BMC cấp nguồn 5V cho CPU như BIOSTAR M7NCG và một số BMC AMD khác).

Các bộ nguồn ATX 2.x có đường điện chính là đường 12V, đều có trang bị đầu cấp nguồn SATA, PCie (VGA) bên cạnh những đầu cấp nguồn HDD, FDD thông thường. Hiệu suất của bộ nguồn ATX 2.x thường đạt trên70%. Xu hướng chuẩn ATX 2.x đang dần thay thế chuẩn ATX 1.3.

Chuẩn ATX

V 2.x

V 1.3

3.3 V

32 A

35 A

5 V

40 A

50 A

12 V 1

18 A

30 A

12 V 2

18 A

-

Tổng công suất

550 W

550 W

Khác biệt giữa các chuẩn ATX

 

V 2.2 / V 2.1

V 2.01 / V 2.0

V 1.3

Đầu cấp nguồn

24 pin

24 pin

20 pin

Số đường 12 v

2

2

first

Đầu cấp nguồn SATA

Have

Have

-

Hiệu suất thấp nhất

72%

70%

60%

Đường điện chính

12V

12V

5V

Hồ Quang Ngọc
quang_ngoc2006@yahoo.com