Should You Buy a Modular Power Supply? The Full Answer

Last updated Jan 28, 2022

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An example of a semi modular power supply unit

Some questions have a simple yes or no answer. Do you want extra toppings? Do you like Justin Bieber? Should you buy a modular power supply unit?

Unfortunately, not everything is as simple as liking Bieber. Each of us has different wants and needs and different demands from his/her computer. And thus, a fully modular power supply unit is better for some, a non-modular power supply unit for others, while most people would likely be better off with a semi-modular one.

What is a Modular Power Supply?

Modular power supplies are simply power supply units with detachable cables. With that said, there are minor differences between fully-modular and semi-modular PSUs.

Non-modular vs. Semi-modular vs. Fully Modular

The main difference between the different types of PSUs lies in how they treat their cabling. Non-modular power supplies have all cables permanently attached. Semi-modular power supplies have some cables attached (the most important ones). And fully modular power supplies, as the term suggests, come with no cables attached.

Intermission: What is a PSU?

The Power Supply Unit, or PSU for short, is the part of the PC that directly connects to a wall outlet and brings power to the rest of your system. This makes it the most important part of a computer, for it could be the hero that takes the bullet to save your PC. It can keep at bay a surge of electricity during an electrical storm, sacrificing itself to keep everything else safe.

Choose a bad PSU and it can also be the villain who decides to fry everything else. With no storm or bursts of electricity. Just because.

The primary difference between non-modular, semi-modular, and fully modular power supply units is that you can detach some or all of their cables at will. This modularity might sound awesome, but, well…that’s not always the case.

Non-modular Power Supply Units

Before someone had the bright idea to make their cables detachable, all PSUs where what we today classify as non-modular. All cables were constantly attached, cable management wasn’t really “a thing”, and most people didn’t even know cable clutter could turn into a problem. Modular PSUs helped in that regard, but there are still situations where non-modular PSUs excel.

EVGA 500W 80PLUS Certified PSU

An excellent non-modular power supply unit.

04/08/2024 07:25 pm GMT


+ Cost-effectiveness
Thanks to capitalism, prices dropping, technology improving, and their design remaining rather static for decades, you can find truly stellar non-modular PSUs for much less than their modular counterparts. If you’re on a fixed budget and you have to choose between a genuinely good but non-modular PSU or a mediocre but modular one, go with the more reliable PSU.

Remember, every other component of your PC relies on this specific unit.

+ Smaller footprint
Modular and semi-modular power supply units contain extra hardware that allows their cables to be detachable. Non-modular ones don’t need such extra internal cables and connectors, freeing up that space. This makes them more compact as far as the units themselves go.

+ Good for “power users”
There’s a category of power users who end up using all available ports on their gear, be it a motherboard or a PSU. If you’re one of them, there’s no point in paying for modularity: you’d end up connecting all of them anyway.


Cable mess
Having all cables perpetually attached to your PSU means that you will have to manage both the cables you use and the ones you don’t. If your PC case doesn’t offer stellar cable management features, or you haven’t read our cable management guide, you will end up having a mess of cables in your PC. You might also experience…

Increased temperatures
Fans cool our PCs by sucking cool air and blowing out hot air, creating air paths over the components of our PCs. A bunch of excess cables in their way can restrict airflow, leading to lesser cooling and higher temperatures. That generally isn’t good for the longevity and performance of your PC.

Fully Modular Power Supply Units

You’ve read about non-modular power supply units and decided that, nope, you don’t want your PC’s performance dropping or a cabling nightmare. You know a modular PSU is right for you. But is it? Or should you go semi-modular?


+ Cooler temperatures
The biggest advantage of modular power supplies is you can remove any cable you don’t need. Most users need only four or five cables. This leads to better cable management, better cooling and lower temperatures, which translate to better performance for the rest of your hardware.

+ Easier cable management
Having no useless cables dangling around helps when dealing with the ones you need. It also makes it easier to figure out what connects where and to cable manage them.

+ Better aesthetics
The lack of tangled multicolored cables can help a lot with the aesthetics of your build. Let the LEDs shine through! Fully modular power supplies also give you the option of custom cables.

+ Easier to clean
With a modular power supply unit, instead of having to remove a stiff 20/24-pin connector from the motherboard, just disconnect the PSU side of the cable. There, problem solved!

+ Ability to replace cables
Being able to remove any single cable means that you can also replace it. It’s rare for a single cable to get damaged but it can happen. And when it does with a non-modular PSU, you have to replace the whole unit.


Connectors can fail after repetitive use
The first modular power supplies didn’t have the most reliable connectors. Because of problems with some of them, people used to think all modular PSUs were less reliable than their non-modular counterparts.

Although this isn’t a problem anymore, that doesn’t mean the improved connectors in newer PSUs are designed to be repeatedly connected and disconnected, day in and day out. As Murphy’s Law states, anything that can fail will fail. Don’t overdo it.

Initial Complexity (for new builders)
Having no cables attached by default means that you’ll have to connect everything yourself. If you are new to building PCs, having to deal with a bunch of exotic cables might seem too complex. Don’t worry, you’ll pull it off, but you will have to pause sometimes to figure out what goes where.

Larger Footprint
Those removable cables have to connect somewhere. And that “somewhere” consists of extra cabling and ports, that end up making modular PSUs larger than their non-modular brethren. It would be best to check out the available space in your PC case before buying one.

Semi-modular Power Supply Units

Semi-modular power supply units offer the best but also the worst of both worlds. Strangely, this mix of characteristics makes them a better choice for most people.


+ Easier for new builders
Semi-modular power supply units are by far the easiest for new builders since most necessary cables come pre-attached. “Most” because some models might come with only one of the following cables pre-attached and others with all of them:

  • 20/24-pin ATX power connector: powers the motherboard and its on-board components.
  • 8-pin CPU connector: provides power to the CPU.
  • PCIe connector: “feeds” your power-hungry GPU
  • SATA/MOLEX connector: connects to storage devices like HDDs, SSDs, and the occasional fan or front panel/extender.


Fixed cable length
If a cable is too short, it might not easily reach a component. Too long and it can add loops to the cabling chaos. With a modular PSU, you could swap it for one that’s just perfect. With non-modular and the pre-attached cables on semi-modular ones, you’re stuck with what you got.

Dangerous to attach the wrong cable
Although they might look the same, cables in both modular and semi-modular PSUs can be incompatible. When dealing with removable power cables, always check the device’s manual. Double-check every cable and connector. Never mix or swap them. And when buying a replacement cable, make sure it’s compatible specifically with the PSU you’re buying it for.

Limited Aesthetic Options
Since at least some cables are fixed, semi-modular power supplies share the same problem with non-modular ones: those cables can look ugly in specific builds, where you might want to have uniform coloring.

Can You Just Choose Any of Them?

Assuming the power supply is compatible with your motherboard and can provide enough energy for your components, yes.  The option to detach cables is only a luxury. Unlike their cable connectors, most PSUs aren’t that different. They’re designed to power the same types of hardware in the same way.

How Many Watts Should Your PSU Be?

Your main priority when buying a new PSU is to give your computer the power it needs. To figure out how much wattage you need, you can enter your PC components into a power supply calculator like OuterVision’s.

My results on OuterVision's power supply calculator.

It’ll give you a rough idea of the wattage level you should look for in a power supply. But beware, just because the calculator said 450W doesn’t mean you should go buy a 450W PSU.

True performance and certifications

The wattage mentioned on a PSU’s packaging is usually its peak performance. Your average car might be able to reach 200 mph but it isn’t designed to keep going at that speed. Similarly, a PSU’s peak performance means that it can offer that amount of power, but only for a limited amount of time.

As a rule of thumb, you’ll be safe purchasing something with 20%-30% more wattage than what your build needs. If you calculated you need a 700 W PSU, check models in the 850-1000 W range. That way, you won’t overload it and you’ll have some leeway for future upgrades.

It’s also worth spending some extra money to buy a power supply that carries a higher 80 Plus certification. You’ll end up getting it back thanks to somewhat reduced electrical bills. And that’s because the higher the 80 Plus specification, the better a PSU manages electricity.

Closing Thoughts

Whatever you end up buying, we’ll bid you farewell with something we’ve learned through the years: buying a good PSU is an investment. When your PC can no longer handle the latest games, upgrading your GPU or CPU can remedy the problem.

But just like your monitor, keyboard, and mouse, your PSU could very well remain the same between many builds. That’s why you should treat it as a priority.

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  1. Herman Thomas

    Great read, thanks for the information. I have built a couple PCs before, but never truly thought about the power of the PSU. This info will help me explain to my son the purpose of the PSU as we tackle his first build. Wish us Luck and thanks again!

    • Thao Tran

      Good luck! Sounds like your son is in good hands.


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