Knowing the connectors that our power supply uses and where they should be connected is important. The truth is that these connectors have a unique and different design, which prevents the wrong connection. But, even so, you need to know how to connect each of the connectors correctly.
The good thing about the power supply is that they have few types of connectors, in fact, it has been reduced a lot in recent years. Note that several new power connectors have appeared. We will see all the connectors, both the obsolete ones and the new ones, although the latter are rarely used.
24 pin ATX
This is the main power connector for the motherboard. Currently, this connector is usually already a single 24-pin connector, but in some cases we have a 20-pin connector and an extra 4-pin connector. The reason for this second type of connector is that some older motherboards used a 20-pin connector, but it is deprecated.
Note that this power connector has five pins not present in other connectors. These pins have the following particularities:
- PWR_OK or Signal Power Good: Its mission is to prevent the PC from working at inadequate voltages, “warning” the motherboard of a possible power supply malfunction. This signal is generated after a series of internal source checks. We have to say that this signal is 5V, so poor quality power supplies inject it directly from the 5V rail, so the motherboard thinks everything is ok
- 5VSB rail: This pin is assigned to standby, which remains active as long as the source is connected and the switch is on. This is maintained even if the computer is turned off and it is important to power any device that remains in standby.
- -12V Rail: This is little known and the truth is that it is falling into disuse because it does not have a relevant function
- Power Supply On: Its function is to keep the power supply on or off, as needed. When we press the power button on the PC, this signal is activated to start the system. Power off when motherboard open circuit
- Empty pin: Pin 20 was intended for the pin dedicated to the -5V rail, which currently no longer exists and is totally deprecated
ATX12VO
The ATX connector was born from the hand of Intel in 1995 and has had several revisions. Recently Intel has decided to go a step further and has developed the ATX12VO connector , designed to reduce consumption. The number of pins is reduced to less than half compared to the 24-pin ATX connector , eliminating the 3.3V and 5V rails.
This connector has only 10 pins, forcing the motherboard to have voltage converters . It has the peculiarity of having a +12 VSB pin that is reserved for the power switch. In addition, it has three +12 V1 DC pins that supply 12V and must be converted to the necessary voltages.
EPS 4+4 pin
Power connector or connectors that have the mission of powering the processor. We say connectors, because some high-end motherboards require up to two of these connectors.
It is usually a 4 + 4 pin connector , connectors with only 4 pins are obsolete. This is due to the fact that modern processors have a high consumption and often require all 8 pins. It not only feeds the CPU, but also the elements it integrates such as graphics, memory controller, etc.
These connectors began to be used with the Intel Pentium IV processors and are still used today.
SATA power
We are going with the connector used in modern SATA hard drives , whether they are HDDs or SSDs. Although it was created for storage units, it is now also used for LED controllers, liquid coolers, etc.
Something quite particular about this connector is that it offers voltages of 3.3V, 5V and 12V . It also has the peculiarity of not being a symmetrical connector, but rather it has a particular design. If we see it, it looks like an “L” lying down, allowing only one type of installation.
It should be noted that there are several unusual variants of this connector. A special one for laptops and another for SAS hard drives that carry power and data together in the same piece.
6+2 pin PCIe
This connector is mainly used to power graphics cards. This is used when the graphics card has a consumption that exceeds 75W, which is the power that can be supplied by the PCI-Express connector on the motherboard. Note that some high-end or overclocking motherboards may require one of these 6-pin PCIe connectors.
The PCI-SIG standard states that the 6-pin PCIe connector can offer a maximum power of 75W and the 8-pin PCIe connector can offer up to 150W.
We must emphasize that the 2 additional pins do not add additional power . What these two connectors do is add the “sense wire” function . It acts as a kind of sensor, which allows that when the requirements of the graphics card increase, the power supply can give more precise control.
We have to say that this function is now out of use , not currently being necessary to control the voltages properly. What is done by the manufacturers is to assign it as a negative pin so that the graphics card works, otherwise the graphics card could not boot.
12VHPWR connector
this is a cone
created by Intel and used by NVIDIA for its RTX 30 Seris graphics cards. While intended for use with PCIe 5.0, it is not unique to this connector, but does require PCIe 5 certified power supplies. It seeks to replace 4+4-pin PCIe connectors , offering a single connector that can supply more power.
Modern graphics cards typically have two or three 8-pin PCIe power connectors. This means a power supply of up to 450 watts, plus the 75 watts offered by the PCIe x16 port. The 12VHPWR connector wants to correct this problem with a single 12-pin connector that should simplify everything.
This connector offers several peculiarities. The first thing is that it allows four powers, starting at 150 watts , going through 300 watts , 450 watts and reaching up to 600 watts . Theoretically this connector, in the future, could support about 1000 watts.
4-pin Molex (deprecated)
Something quite interesting about this four-pin connector is that its name is incorrect. Actually its name is peripheral connector , although it is usually referred to as a Molex connector. This connector’s “popular” name is because it was designed by the Molex Connector Company , just like other power connectors. Although it is not entirely correct to call it Molex, the truth is that it does not matter, it is accepted as such.
This four-pin Molex connector is falling out of favor. Originally , it was mainly used with mechanical hard drives based on the IDE data connector. It has also been used for a long time for other elements such as liquid cooling or RGB lighting . On some older motherboards it was even used to power PCIe ports or as supplemental power on older motherboards for overclocking. It is currently mostly superseded by the SATA power connector.
4-pin floppy (obsolete)
Currently, if not on very old computers, it is (almost) impossible to see on modern power supplies. The Floppy connector was mainly intended for floppy drives and in some specific cases, it was used for fans, but little else.
This connector is quite curious, since Floppy is not its correct name either. Actually its correct name is FDD , but since it was used for floppy drives, the name Floppy remained. Also known as Berg , the company that designed this power connector.
Technically this connector is exactly the same as the IDE, but in a more compact version.
