How to choose a PC power supply. Where can i buy a pc power supply

If you are going to run an SLI / Crossfire setup, you should make sure the rail (s) + 12V is delivering not less than 34A in total. Different power supplies are labeled differently – some show the maximum amperage supplied by each bus, while others provide a maximum combined maximum power, e.g. 396 W, which equals 396 W / 12 V = 33 A.

PC Power Supply Buying Guide – How to Choose The PSU For Your Gaming PC

The PSU is certainly one of the most underrated and underrated components in a gaming system. First-time builders usually have a hard time finding and selecting the best power supply for their needs. This is simply because there are hundreds of power supplies on the market and too many variables that come into play when making a purchasing decision. However, making the wrong decision when purchasing a power supply can later have detrimental effects.

A power supply is often considered the heart of a gaming machine or any PC. Just as the heart supplies blood to all organs, the job of a power supply unit is to make sure that the computer’s components receive a clean, steady flow of electricity. Failure to do so can lead to a host of problems, ranging from minor inconveniences like fan noise to catastrophic failure and even the death of many components inside the system. Therefore, the power supply is one of the most important components of the system that requires special research and attention when making a purchase decision.

More efficient units such as this AX 1600i from Corsair are not needed by everyone – Photo: Corsair

What is a Power Supply?

An ac power adapter or adapter is what converts AC power from a wall outlet to the DC power required for computer components to function. Unlike home appliances, PC components require a constant, steady flow of DC current to function properly. The power supply provides clean and efficient AC to DC conversion and then delivers it to the specific components that need it. The AC adapter may not directly affect the aesthetics or performance of the computer, but without the AC adapter, the computer will not even turn on. Therefore, it is a basic and necessary part of your computer that needs to be properly thought out and paid attention to.

There are a few key features that you should pay attention to when purchasing a power supply. The list can be a bit overwhelming at first, but all of these items are quite simple when considered individually, and even a novice computer builder should be able to choose the best power supply for their system if these parameters are taken into account. Let’s go through them one by one.


Before choosing a power supply, you need to find out how much power you will actually need from the power supply to start your computer. It should be distinguished here that the power supply does not “supply” energy, but the computer components “draw” energy. Therefore, having a larger power supply will not automatically increase your electricity bills.

There are two ways a user can estimate the amount of energy his system needs.

  • Finding power consumption benchmarks from sites like Tom’s Hardware or YouTube channels like GamersNexus for individual system components (mainly CPU and graphics card) and then adding them together, leaving extra headroom for smaller devices like drives and fans . This should give the minimum power rating.
  • Using one of the many PSU power calculators, such as the one from OuterVision. These calculators will give you an estimate after considering the components in your construction. Keep in mind that these calculators will often overstate your components’ power consumption and may suggest a power supply that is larger than you need.

Generally, you should leave approximately 150-200 watts of extra power reserve in your PSU. This means that if the sum of the power consumption of all components under load is up to 650W, an 800W unit should be a good choice for this set of equipment. This should give you plenty of room to upgrade or overclock if you see fit.

While it is a good idea to leave the necessary power reserve in watts of your power supply, buying a power supply with a few hundred watts is not one of them. If you buy a 1000W power supply for your computer that can only draw up to 650W under load, you’re essentially wasting money on capacity that you’re not using.

Not buying a power supply is also a big no. Don’t underestimate the needs of your PSU by purchasing exactly the capacity you think your system will be drawing at its peak. In our example, buying a 650W unit would be a bad idea as any current spikes or voltage spikes will shut down the PSU and force a hard restart under load. Therefore, ensure plenty of headroom while keeping overall performance within reasonable limits.


Another important factor to consider when making a purchasing decision is power supply performance. Power supplies have different levels of efficiency and are “rated” according to their efficiency. But what do power supplies need to be efficient at? As we sneaked out before, the power supply converts the AC from the wall to the DC required by the components. However, some energy is naturally lost in the process as waste heat. A good power supply will convert about 80% of incoming energy into DC. A really good power supply may be able to convert over 90% of the energy it consumes. Therefore, a more efficient power supply is better.

This 650W model is fully modular, has enough capacity to run your entire gaming rig, is rated 80 Plus Gold, comes with a seven-year warranty, and has a strong 12v line. The fan may be a little noisy when pressed with heavy load, but it’s not something you’ll notice well above the other fans spinning inside the case.

Power output: How much do you need?

cryorig taku case overview (2)

While there are some important factors to consider when choosing a power supply – as with any computer component – identifying one of the most important is refreshingly simple. You don’t have to wade through benchmarks or read reviews to know how much power output you need. Instead, you can use a tool like the Newegg power calculator to work out exactly how much power your new PSU needs.

To use the tool, you need to select components from the drop-down lists for each category. The above tool is up-to-date with the latest options for Central Processing Unit (CPU), Motherboard, Graphics Processing Unit (GPU), Random Access Memory (RAM), and more. While the tool doesn’t go into the details of each component, it does so where needed and takes the guesswork out of deciding how much power you need.

For example, if you are building (or purchasing) a computer with an Intel Core i7-11700K processor, an Nvidia GeForce RTX 3070 graphics processor, 16 gigabytes (GB) of RAM consisting of two 8 GB memory, 1 TB SSD, and a hard drive with a capacity of 1 TB 7200 rpm (HDD) then 512 watts of power would be recommended. You can choose a 600W PSU to be on the safe side – and purchasing the option you want is just a click away.

Anticipate upgrades when buying a power supply

motherboard graphics card

Of course, you may want to run a few scenarios to make sure you can cope with your long-term needs. For example, upgrading to an Nvidia GeForce RTX 3080 graphics card raises the recommendation to 602 watts, while doubling the RAM makes no difference. If you think you can upgrade your GPU then you will need a power supply with at least 700W.

You get the picture. Don’t just plan today to meet your needs, instead look a bit ahead and think about what changes you might want to make later. And if you’re buying a ready-made PC, make sure you know what power supply it’s using to make sure it can handle anything you want to add – or that it’s easy to replace at some point.

Important note on power: continuous power and peak power are different things. In general, the “maximum power” number of a power supply refers to the continuous (stable) power that a power supply will continuously deliver, while peak power refers to the increased maximum (overvoltage) power that a power supply can deliver, albeit for a very short amount of time. (e.g. 15 seconds). When buying a power supply, make sure that its continuous power meets your needs, otherwise you will likely run into problems when your computer is running at full load.

Finally, don’t worry that purchasing a higher wattage PSU means you’ll definitely be using more energy. The power supply will only draw the electricity required by your computer’s components – so while buying a larger power supply might be a waste of money upfront than you need, it won’t cost you more to use your computer because of it.


Some power supply manufacturers have built in safeguards to protect components from power problems. These protections often increase your power costs, but can also provide added peace of mind.

The first is overvoltage protection, which refers to a circuit or mechanism that shuts down the power supply if the output voltage exceeds a certain voltage limit, which is often higher than the rated output voltage. This protection is important because high output voltages can damage computer components connected to the power supply.

The second is overload and overcurrent protection. These are the circuits that protect the UPS and the computer by shutting down the UPS when excessive current or power loads are detected, including short circuit currents.

After qualifying for titanium 80+ certification, this power supply has the highest level of performance and efficiency that can be obtained from a power supply.

Got Good Leads? Getting to Know PSU Cables

The individual cables that come out of the computer’s power supply are often referred to as “wires”. Intel’s original ATX power spec only required a 20-pin connector on the motherboard, and a separate “P4” square four-pin connector was later added to provide a 12-volt cable for independent power supply to the CPU. (The latter feature appeared in a specification update called “ATX12V”). The later EPS12V standard expanded the ATX main cable to 24 pins to provide extra power for PCI Express (PCIe) slots and doubled the dedicated CPU power connector to eight pins.

When graphics cards began to require even more power than the PCIe slots could provide on their own, power supply manufacturers added six-pin additional PCIe power cables to the power supplies. And some high-end graphics cards eventually needed even more power than a single six-pin connector could provide, leading to power supply designs with eight-pin PCIe cables, dual six-pin cables, and even combo eight- and six-pin cables plugged into any slot (sometimes called “6 + 2” conductors).

Two-standard split connectors commonly found in modern power supplies (from left to right): ATX / EPS motherboard power (20-pin / 24-pin), ATX12V / EPS12V CPU power (four-pin / eight-pin) and an additional eight-pin PCIe slot / sixopin (aka “6 + 2”)

Until recently, and with the rise in popularity of M.2 SSDs, most PCs had at least a few bay-mounted hard drives or 2.5-inch SSDs (and previously internal optical drives) that complied with the Serial ATA (SATA) standard. Separated from the SATA data cable, SATA drives use their own separate SATA power connectors, distinctive thin “L” connectors that can only be inserted one way.

Other internal peripherals such as liquid cooling water pumps and fan hubs can still use the classic four-pin ATA power connectors. They are commonly referred to as “Molex connectors” (but contrary to popular belief, they are usually not manufactured by Molex). Some sound cards and front-bay controller panels, until recently, even used the old four-pin floppy power connector. But that old-fashioned connector is lost in modern power supplies.

Most power supplies have enough physical wires for all the equipment you want to disconnect from a power supply for its power. But you want to be especially sure to double-check whether you’re installing a PSU on a system with older hardware or building a PC with a monster video card.

All Mod Cons: Understanding Modular PSU Cables

As more and more cables protruded from the power supplies, it became more and more obvious to PC builders and builders that hiding unused ones in a large package between the power supply body and the case was not a good solution. That’s why most of today’s top-quality power supplies use modular cable connectors: that is, cables that can be plugged in as needed, skipping over unused ones, to reduce clutter.

Power supplies that only have removable cables are called “fully modular” power supplies, and those with a few cables permanently attached are called “semi-modular”. Why not make every cable modular in every project? The added socket connectors increase cost, provide some resistance, and reduce performance, which is why so many high-end power supplies include at least a soldered main (24-pin) motherboard cable. (After all, everyone will have to use at least this cable on any computer.) Fully modular, 100% removable cable designs only make sense for PC builders and modders who use non-standard length cables and may want to replace the 24-pin main lead something shorter.

Note that while some power supplies from different manufacturers use the same type of modular jack (and cables from one brand may fit into the enclosure of another brand’s power supplies), not all are wired the same way. Users should always connect only modular cables that are intended for use with their specific model or series of power supply. Don’t grab the leftovers, mystery modular cables from the parts box, and plug them into another modular power supply, hoping they’ll work – unless you like fireworks and want to buy new PC parts!

As mentioned at the end of the previous section, when evaluating a PSU you should look at installed components and peripherals that require a dedicated power connection. Most modern power supplies provide more than enough connectors to power any reasonable number of SATA devices or Molex-powered auxiliary peripherals.

The key “question mark” connectors will be the PCIe slots – specifically, how many you will get on a given power supply. You need to make sure you have the necessary cables for each graphics card or cards you install. The “6 + 2” connectors we mentioned earlier can be plugged into the six- or eight-pin power jack on your graphics card. However, a PCIe power cord, which only has six pins, won’t be enough for the eight-pin socket on your graphics card.

Note that some very high-end graphics cards these days actually require three six- or eight-pin PCIe power cords, and only some high-powered power supplies will provide you that much. (Some may only give you two.)

Also note that some recent Nvidia GeForce RTX 3000 Founders Edition cards use a special proprietary 12-pin power connector on the end of the card that connects to the power supply cables via an adapter or splitter (provided by Nvidia with the card).

Nvidia GeForce RTX 3080 Founders Edition card with a 12-pin power connector at the top (Image credit: Zlata Ivleva)

In that case, don’t be fooled by looking for a PSU with native 12-pin PCIe GPU connector; it is not a thing.

Of course, as with anything, we recommend that you check the dimensions of your computer case first to make sure the power supply you have your eye on will fit inside.

Power Supplies – Showing 1 – 24 of 14196 Products

The computer power supply is one of the most important components of the computer because it is responsible for ensuring stable and regulated power to the system. If you are purchasing a power supply for your computer, there are several important criteria to consider when finding the perfect power supply. These criteria include enclosure size and form factor, system power requirements, performance, and internal cabling preferences.

Size Standards

Computer power supplies come in a variety of sizes and forms. It is essential that the selected power supply unit (PSU) meets the size requirements of the chassis and motherboard. If you have a Mini ITX case, for example, you cannot use a standard ATX power supply. For more information on PSU form factors, see below.

  • ATX
    Standard PSU size that will fit most medium to full-size towers. Some micro ATX cases can also use ATX power supplies.
  • Mini-ITX
    Mini ITX power supplies are designed specifically for mini ITX systems, but may also fit into other small computer cases.
  • SFX
    SFX computer power supplies are smaller than standard ATX power supplies and are designed for micro ATX computer cases and other small sizes.
  • TFX
    Another compact computer power supply that is thinner to fit micro ATX, Mini ITX, and other smaller systems.

The power rating of a computer power supply is a measure of how much power it can deliver to your hardware. When buying a power supply, you should consider how much energy your computer system requires. To calculate the system power requirement, add up the power consumption for all components.

Start with the motherboard and CPU, then include graphics cards, system memory, storage devices, and other expansion cards. For an even better estimate, include USB devices, internal fans, and other accessories. After estimating, try to find a computer power supply that is at least capable of doing this. For a greater margin of safety, you should get a PSU well above this minimum.

Cable Management

There are two cable management options for computer power supplies, modular and non-modular. Modular cabling allows internal power cables to be connected and disconnected from the power supply itself, preventing unused cables and connectors from sagging inside the case. Computer power supplies with modular cabling typically cost more than power supplies without it.


The efficiency of a computer power supply is the ratio of the amount of power it supplies to the amount consumed. For example, a power supply that provides 200 watts of power but draws 400 watts from an outlet has a 200/400 or 50% efficiency factor. The more efficient your computer is powered, the less it will cost you to run it.

One measure that can be used to evaluate performance is the 80 PLUS® certification level the power supply has, if any. The different 80 PLUS certification levels include 80 PLUS, 80 PLUS Bronze, 80 PLUS Silver, 80 PLUS Gold, 80 PLUS Platinum and 80 PLUS Platinum. The most basic certification is 80 PLUS, which means an efficiency index of at least 80%. The other certifications range from bronze to titanium, the latter being the highest available. If your computer’s power performance is a big concern for you, try finding one that has a high level of 80 PLUS certification.

Now efficiency is one thing to pay more for, but the more vague “quality” of production matters more. And the quality exceeds the quantity of power supplies, as a typical 800W unit is much more prone to failure under a 400W load than a 450W unit from a top quality supplier.

Frequently used formats of PC power supplies

PC power supply

In older computers, the power supplies are still available in AT (Advanced Technology) format. The main power supply is provided by a two-part plug, the individual parts of which have 6 pins. However, in modern desktop computers, AT-format power supplies are no longer important. Therefore, the use of such models with the current motherboards is excluded. Currently, the standard for PC power supplies is the ATX format. According to the specification, such a power supply has the dimensions of 140 x 150 x 86 millimeters (L x W x H). In fact, the length is regularly exceeded, especially with more powerful power supplies. Width and height are respected to ensure trouble-free installation in any ATX computer enclosure. With older ATX power supplies, the processor is powered from a 4-pin plug, while with the current equipment.

SFX or SFX-L standard is also available, especially for particularly compact enclosures. The cables are identical to those of a conventional ATX power supply; only the number of connections available for DVD drives and hard drives is typically less. The dimensions are 100 x 125 x 63.5 mm (L x W x H). If the length exceeds 100 millimeters, it is referred to as the SFX-L power supply. They usually have a 120mm fan, while a normal SFX power supply can usually only install an 80mm fan. Thin Format Factor (TFX) power supplies are designed for ultra-thin computer cases. The dimensions here are 175 x 85 x 65 millimeters (L x W x H). Even in this case, the existing connecting cables are no different from a “normal” ATX power supply.

Thanks to the integrated smart Zero fan, you will not hear any noise from the power supply until the load exceeds 40%, and even then you will hardly hear it work.

Best 1000W PSU: be quiet! Dark Power Pro 12

be quiet! Dark Power Pro 12

source: Rich Edmonds / Windows Headquarters

  • 1000 W output
  • Rating 80 Plus Titanium
  • Incredibly efficient
  • High quality
  • 10-year warranty
Category be quiet! Dark Power Pro 12
Power 1000W
Modular Fully
Efficiency 80 plus titanium
Shape factor ATX12V
Cooling 1x 135mm fan
PCIe connectors 8
Guarantee 10 years

be quiet! manufactures high-quality PC components, and the company’s power supply series is famous for low noise and stable operation. Take these features and add the performance of 1000W and 80 Plus Titanium and you get be quiet! Dark Power Pro 12. This 1000 W unit is an absolute giant in providing energy.

It’s expensive – I’m talking about the price of an expensive GPU or CPU – but you get a fully modular PSU with a 135mm fan to keep things cool under load. There are eight PCIe connections available, which shows just how serious this PSU is in delivering power, and you can choose between 12v multi-rail or monorail mode.

Best 1000W PSU

be quiet! Dark Power Pro 12

For serious PCs

You probably don’t need a 1000W PSU, nor should you reserve a good chunk of your budget to buy one. But it is one of the best power supplies.

Best SFX: FSP Dagger Pro

FSP Pro 850W dagger

source: Rich Edmonds / Windows Headquarters

  • 650 W output power
  • 80 Plus Gold Rating
  • Very efficient
  • High quality
  • Compact size
Category FSP Pro Dagger
Power 650W
Modular Fully
Efficiency 80 plus gold
Shape factor ATX12V
Cooling 1x 92mm fan
PCIe connectors 2
Guarantee 7 years

FSP is a power supply manufacturer that makes devices for other companies, including be quiet! They create robust power supplies that are reliable and provide clean and stable power to the connected equipment. We’re big fans of the FSP Dagger Pro series of SFX units which are well designed for use in more compact computers.

This 650W model is fully modular, has enough capacity to run your entire gaming rig, is rated 80 Plus Gold, comes with a seven-year warranty, and has a strong 12v line. The fan may be a little noisy when pressed with heavy load, but it’s not something you’ll notice well above the other fans spinning inside the case.

Best SFX

FSP Dagger Pro

FSP makes great power supplies for other brands, and it’s also worth considering your own collection of power supplies.

The selection process was fairly simple. First, we decided to identify the community’s needs when it comes to power supplies. With our findings in mind, we created criteria that helped us choose the products that you will see today.

Picking the Right Power Supply For Your Gaming PC

If you’re reading this part of our guide and reviews, there’s a good chance you’re having trouble choosing the right power supply for your gaming hardware.

The purpose of this guide and review is not only to provide you with the best power supplies on the market, but also to help you choose the best one that best suits your needs and budget.

To help you with this, here are three very important scenarios along with the best power supply for each of them. So hopefully by the end of this section you would find a power supply for your gaming PC.

Scenario 1: You own or plan to build a relatively inexpensive gaming PC – similar to our top under the $ 500 recommended for gaming PCs. That’s why you’re not really looking for a super-efficient PSU and want everything to be as cheap as possible.

For this scenario, we recommend our inexpensive Corsair CX 450M.

Scenario 2: You have plans to upgrade or build a gaming PC that is relatively powerful (with support for a 2080 GPU or higher), and you don’t mind spending a little more money buying a power supply to give your kit the power it needs.

In that case, we recommend our best power supply up to 750 W, the EVGA SuperNOVA.

Scenario 3: You are building real power. Your system requirements are over 1000 watts and money is no problem. For this scenario, we recommend our most powerful power supply from our list, the Thermaltake Toughpower PF1.

Final Thoughts

You won’t need a power supply with more than 750 watts of power if you’re running a single GPU gaming platform, even if you’re planning a potential upgrade to a range of different components like motherboard, RAM or CPU.

Some of the PSUs we wanted to be part of in our final selection that unfortunately haven’t been introduced include the SilverStone SX500-G technology, the Seasonic X-850 and the Thermaltake Smart RGB PSU. The reason is that they were either not rated high enough or were a bit more expensive than we think they are worth.

Choosing a super-efficient power supply like the Apevia ATX-JP1000W or any power supply over 1000W only makes sense if you’re building a multi-GPU gaming platform that requires a lot of power.

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