How to Choose a PC Power Supply for your System

The power supply is an essential component of any PC design that is sometimes overlooked and underappreciated. A power supply unit (PSU) is used to power all of the components in your PC, as its name would imply.

Power supplies include a wide range of features, just like computers and hard drives. Every user has unique power requirements, which might differ greatly from person to person.

It can be tempting to purchase any power source to power your PC, but that is a bad idea. Instability that can be difficult to pinpoint is one of the many issues that can result from a power source that does not deliver dependable or clean electricity.

In fact, a failing power supply frequently results in other issues like erratic resets and freezes that could otherwise go unnoticed. Here is a thorough guide to help you choose the best option if you’re unsure of what power supply you need to invest in.

What is a Power Supply?

Every PC’s foundation is made up of power supply components. These components transmit power throughout your PC by snatching it from the wall outlet. Your machine won’t work as you need it to and might not even turn on if you don’t supply it with enough electricity. A PSU can protect components during a PC crash or offer fail-safes for errant currents in addition to providing power.

It is possible to define the power supply as an electrical equipment used to supply power to electrical loads. This device’s primary purpose is to convert the electrical current coming from a source into the precise voltage, frequency, and current needed to power the load. These power supplies are also referred to as electric power converters on occasion. While certain sorts of supplies are constructed inside the appliances they operate, others are made as independent pieces of cargo.

Types of A Power Supply

Following are the different types of a Power Supply that are classified:

1.    SMPS- Switched Mode Power Supply

One sort of power supply with a switching regulator for effectively converting electrical power is an SMPS power supply, also known as a computer power supply. This power supply, like other power supplies, changes the properties of current and voltage when transmitting power from a DC source or AC source to DC loads like a PC.

2.    Uninterruptible Power Supply (UPS)

An electrical device called a UPS (uninterruptible power supply) enables a PC to continue operating for a while even when the primary power source fails. Additionally, this device is shielded from power flow. When a UPS detects a lack of power from the primary source, the battery stores the energy.

For instance, if you are using a PC while the UPS (backup power source) detects a power failure, you must save the data before the UPS discharges. Any data in the RAM (random access memory) of your computer is deleted when both the primary and backup power sources fail. A backup power source prevents power loss when it happens so that damage results.

3.    AC Power Supply

Typically, an AC power supply obtains its voltage from the mains supply. The voltage can then be increased or decreased to the necessary value by employing a transformer, and some filtering may also occur. The various types of AC power supplies are made to provide a nearly constant current, and the o/p voltage may vary depending on the impedance of the load.

In some circumstances, a step-up transformer and an inverter may be used to convert a DC power supply into AC power. Some methods of modifying AC power do not require a transformer.

4.    DC Power Supply

A DC power source is one that offers its load a constant DC voltage. A DC power supply may be regulated from a DC supply or from an AC source, such as the power mains, depending on its design.

5.    Regulated Power Supply

Unregulated alternating current is converted into steady direct current using a fixed circuit known as an RPS (regulated power supply). A rectifier is used to convert an AC power source to a DC power source, and its primary purpose is to provide a constant voltage to a device or circuit that must operate within a specific range of the power supply. Regardless of whether the RPS’s output is bidirectional or variable, it is always DC (direct current).

6.    Programmable Power Supply

The operation of this sort of power supply can be remotely controlled by analogue input in addition to digital interfaces like GPIB or RS232. Current, voltage, and frequency are some of this supply’s controllable characteristics. Applications for these kinds of supplies include the production of semiconductors, X-ray generators, the observation of crystal formation, and automated instrument testing.

7.    Linear Power Supply

Different electrical and electronic circuits employ the LPS (linear power supply) or LR (linear regulator) circuit to deliver DC current to the entire circuit. The voltage regulator, rectifier, filter circuit, and step-down transformer are the key components of the linear power supply. This circuit’s primary purpose is to step-down the voltage of alternating current before switching it to direct current. The following are some of this power supply’s key characteristics. This power supply’s efficiency ranges from 20 to 25%. CRGO core or St Alloy are the magnetic materials employed in this power supply. It is less complicated, bulky, and less complex. It responds more quickly.

8.    Computer Power Supply

The hardware component known as the power supply unit of a computer is utilized to convert the power coming from the outlet into usable power for the various components of the computer. The alternating current is changed into direct current.

Additionally, it prevents overheating by regulating voltage, which the power supply may do manually or automatically. A power converter or power pack are other names for the power supply unit, or PSU.

Different Types of Form Factors of Power Supply

Important information about a power supply, like its size and features, can be learned from its type or form factor. Knowing these common form factors can help you choose the right power supply. Make sure your power supply fits in your case and operates as efficiently as possible by following these tips:

1.    ATX:

Previously, ATX power supplies had a single 20-pin connector for the motherboard’s primary power, but today they feature a 24-pin connector (which is still compatible with older 20-pin motherboards). ATX power supply also provides a 3.3V rail. One ATX feature is soft-off, which enables certain software to shut off the power supply.

2.    ATX12V

Although the performance of the ATX12V specification exceeds that of conventional ATX, both power supplies have the same size and shape physically. The most popular form factor at the moment, ATX12V power supplies come in a range of versions that have been altered throughout time. Versions ATX12V 2.1 and 2.2 are the most recent. The 24-pin main power connector in these models has been enhanced for performance.

3.    SFF (Small Form Factor):

Over the years, numerous tiny power supplies for small cases have been developed. Despite being smaller than standard ATX power supply, these ones are nevertheless functional and perfect for less costly systems with constrained desk space. SFF power supplies include those in the CFX12V (Compact Form Factor), LFX12V (Low Profile Form Factor), and TFX12V categories (Thin Form Factor).

4.    EPS12V:

The 8-pin CPU power connection present in EPS12V power supplies, as opposed to the 4-pin found in ATX12V devices, helps to create a more stable environment for servers. The majority of common home PC components are incompatible with EPS12V power sources, therefore use caution when choosing a power supply.

Different Types of Connectors of Power Supply

It’s critical to comprehend the variations among the several connector kinds used on power supply in addition to form factor. These are the cable ends that plug into each of your various components after leaving your power supply. Certain cables are used by each component of your computer.

The build process can be sped up and inadvertent harm can be avoided by being aware of the connections your PSU supports and the cords to use when connecting your components to your PSU. Make sure the power source you chose is compatible with the rest of your system. What you need to know is as follows:

1.    SATA Power

These cables supply power to 3.5″ hard drives and other SATA storage devices. To avoid having to run enormous amounts of wiring, multiple SATA connections are sometimes found on a single cable. Other devices, such RGB hubs or fan controllers, have recently used SATA power as well.

2.    4/8 PIN CPU

Although the CPU is mounted directly on the motherboard, contemporary CPUs and other motherboard functions cannot be powered by the 24-pin connection. For this reason, CPUs are now powered via 4/8 pin connections.

3.    6/8 PIN GPU

Your GPU or graphics card is connected by 6/8 pin cables. Specific setups are required for GPUs of varying strengths. Because of this, 6/8 pin connections frequently have numerous configurations, such as 6, 8, 6+8, 8+6, and 8+8, on a single wire.

4.    24 pins Motherboards

Different motherboards use power in different ways. Typically, 24-pin motherboard cables provide power to PCIe and other components that are only directly attached to the motherboard.

5.    4 Pin Molex

Currently regarded as ancient hardware, 4-pin Molex connectors are seldom ever used in contemporary systems. On some liquid cooling pumps, Molex 4-pin cables are still present even though SATA connections are more common.

Other Features to Consider – Noise and Cable Convenience

It is crucial to check that your power supply fits within your case and has the correct cables to operate your components. Your pleasure with your PSU can also be significantly impacted by incidental elements that are not essential.

1.    Cabling:

A PSU’s ability to function depends on its cable connections, and the cables that connect your PSU to the other parts of your computer include features that can make cable management easier and let you customize your PC. Three types of power supply cabling are available: pre-installed, semi-modular, and modular.

Modular Power: By allowing customers to connect the bare minimum of cords to each device, modular power supply frees up space. The modular design gives the possibility for customization with unique cables and aids in cable management.

Pre-installed: All relevant cables are already attached to pre-installed or non-modular PSUs, and thus cannot be removed. These components may make construction easier, but they frequently result in dangling cables or extra connectors that clutter the enclosure.

Semi-modular: Combining the two aforementioned designs, semi-modular power supplies have part of their cables pre-installed but leave room for customers to add more as needed.

2.    Noise:

Many people complain about fan noise. A power supply begins to heat up when it begins to output significant wattage. The PSU’s fan speed will increase significantly in response to excessive heat, and it may become very noisy. You may choose a PSU that will power your system without making a leaf blower-like noise by paying attention to things like efficiency and wattage constraints.

Know your Power Supply Buying Needs

Now that you are aware of the essential terms and elements to look for when buying a PSU, it’s crucial to think about the daily power demands and workload of your system. Once you are certain of the essential parts you will be using in your build, you may add and double-check their power usage using a third-party application.

So, if you are aware of how much power the computer will need, you can start researching PSUs and limiting your options based on wattage and efficiency. Be careful because various equipment draws significantly varying amounts of power. Let’s say you need to construct a workstation PC that makes use of a potent CPU and GPU.

These components will consume a lot more power than they would on a computer with integrated graphics, necessitating a larger power supply. On the other hand, if you need to construct a tiny form factor PC for straightforward office use, a less potent PSU can help you save money while still accomplishing the task.

How to Choose a Power Supply for PC – Conclusion

Power supplies have a deciding impact on a project. While less eye-catching than other components, choosing the appropriate PSU is quite important. Details and specs play a crucial role in PSU selection, and you should constantly double-check your power supply and other components to make sure they work together. Here is a succinct explanation of how to select your power supply:

·        Establish the power requirements for your CPU, GPU, and other devices in order to ensure proper operation.

·        Make sure the connections on your PSU match those on your other components.

·        Make sure your PSU will fit in your case by checking twice.

·        Think about long-term elements like cable management, acoustics, and upgradeability.


Here is the list of the best power supply that you can consider from harddiskdirect


Q6718-67005 – HP Power Supply Assembly for HP DesignJet T620 T790 T1120 T2300 Z3200

45J9431 – IBM 280-Watts ATX Power Supply for ThinkCentre M57 Tower