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Difference Between Fully-Modular, Semi-Modular, And Non-Modular PSUs

I was fortunate enough to become aware of modularity before building my PC, so today I will share my knowledge and several hours of research I have on this topic with you.

The difference between fully, semi, and non-modular PSUs is primarily how many cables are permanently attached. Non-modular PSUs have all the cables attached, semi have one or two connected, and fully have no cables permanently attached.

Let’s look into more of the primary differences between these PSU types and how they can impact your build or build budget.

Difference Between Fully-Modular, Semi-Modular, And Non-Modular PSUs

What Are Non-Modular PSUs?

Non-modular PSUs are PSUs with every cable a PSU typically comes with, except the trade-off is they are all permanently soldered into the PSU.

Non-modular PSUs are typically cheaper than the other two varieties, but they aren’t any worse in quality or reliability.

Non-modular PSUs are more straightforward than the other two options for beginners because you can worry less about the setup. Still, I believe everyone should get a semi or fully modular PSU.

The biggest problem with non-modular PSUs is the large number of cables you will have to lay idle in the back of your case.

Other than the obvious visual detriments this has for your PC’s aesthetics; it can also be bad for your case’s airflow.

All those cables you don’t need don’t serve a function, and having them lying there will block air from moving freely through your case.

This can cause some heating issues and may even lead to overheating. However, this situation is more likely in smaller cases. If you have a larger PC tower, your airflow can still be decent enough to avoid this.

The final drawback of non-modular PSUs is that you cannot replace the PSU cables if they happen to break, resulting in you having to buy a whole new PSU in this situation.

Easiest For BeginnersCan’t Remove Unused Cables
CheapestBad Airflow
Cannot Replace Faulty Cables

Pros and cons of non-modular PSUs.

What Are Semi-Modular PSUs?

Semi-modular PSUs are the slightly more expensive alternative to non-modular PSUs that only have between one and three cables permanently attached.

Typically, the permanently attached cables will be the motherboard 24-pin connector, a PCI-e connector, and the 8-pin CPU cable.

Then, the other cables such as SATA, peripheral, and VGA cables will be plugged in as if it were a fully modular PSU.

Or the best part is that you can leave them unplugged and have better airflow than non-modular PSUs.

Speaking from a practical standpoint, semi-modular PSUs are all you will need for a PSU form factor.

The only permanently plugged in cables are going to be cables you will always have plugged in regardless.

You will always have the motherboard, CPU, and PCIe cables plugged into something so that no cables will waste space there.

Then, any additional cables can be added or removed as you need.

The primary drawbacks here are that you will have a slightly more expensive product buying a semi-modular, but it’s not a crazy price hike.

Other than that, you still have the issue of if one of your permanent cables break, you will have to replace the whole PSU.

For beginners to PC, this is the PSU I recommend because it features a reasonable price, good airflow, and the most difficult cables are already plugged in.

Better AirflowSlightly More Expensive
Easy For BeginnersNot As Easy As Non-Modular
Fewer CablesSome Cables Can’t Be Replaced.

The pros and cons of semi-modular PSUs.

What Are Fully Modular PSUs?

Fully modular PSUs are going to be the most expensive and the best looking PSUs on the market.

These are the PSUs with no permanent cables soldered into the PSU by default, and you plug in every cable during setup.

Many people like these PSUs for the airflow and flexibility, but one of the leading reasons for getting fully modular PSUs is customization.

Some PSUs have aftermarket cables explicitly made for that type of PSU, so you can get better-looking cables without the risk of frying your parts.

Most customization options come in the form of extensions that you could technically use on any PSU type. Still, some aftermarket PSU customization will be cables that need to be installed as a power cable.

The most beneficial feature above everything else would be the ability to replace faulty or broken cables.

This allows you to get more life out of your PSU, and if you get past your warranty, you won’t have to replace the whole PSU if the cable breaks.

In the grand scheme of the cost of a PC build, it isn’t all that much more to upgrade from a non-modular to a fully modular, so if you have the money in the budget, I would recommend at least getting a semi-modular.

For most people, semi-modular PSUs are good enough. However, if you are looking for peace of mind or the best aesthetics, look no further than the fully modular form factor.

Best CustomizationMost Expensive
Best AirflowMost Confusing For Beginners
Can Replace Every Cable

Pros and cons of fully modular PSUs.

What PSU Type Should You Get?

If you are looking for the best cable management, customization, and airflow but don’t mind paying the extra cash or the extra work, a fully-modular PSU is going to be the best option for you.

If you can’t quite stretch the cost of fully modular but still want better airflow and cable management, and you don’t want the hassle of plugging in all the cables, you should get a semi-modular PSU.

If you don’t want to deal with plugging cables into your PSU at all and want the cheapest PSU on the market to fit a budget build with no interest in better airflow or cable management, you should get the non-modular PSU.

Are PSU Cables Universal?

PSU cables are not universal, and you SHOULD NOT use older PSU cables or other PSU cables that aren’t made for your PSU type.

Doing so can lead to an issue with the PSU that can end up destroying your SATA drives.

There is no universal standard for PSUs, so if you use a cable made for an entirely different PSU, that could lead to the end of your PC.

If you still aren’t sold on this, look it up on Reddit, and you will find multiple unfortunate PC builders losing tech to their old PSU cables.

Many people think of it as a good idea to save time because they got the cable management just right after hours of fiddling with it, but it is not.

With that being said, if you liked the look of your older cables and that was the reason for wanting to upgrade, there are safe ways to get better-looking PSU cables.

The most popular way to get better-looking cables is to use PSU extension cables that are better looking.

This way, you can still plug in the cables that came with your PSU but get the better looks and compatibility of the PSU extension you choose.

You still need to ensure the PSU extension cables you buy are compatible with your PSU and wattage.

Also, there are full cables that function with certain PSUs, but you have to make sure that it is either made for your exact PSU or the type of PSU you are using.

Brands that make this type of product should have a compatibility list that you can check to ensure your PSU can use those cords.

This isn’t a prevalent way of doing this, though, and it is more likely that you will have to use a PSU cable extension to get better-looking cables.

What PSU Do You Need?

How Much Wattage Do You Need?

The first thing you need to figure out is how much wattage your build requires to function.

This can be done using a PSU calculator or going to PCPARTPICKER and putting all of the parts in your build in the PC builder.

You will then get an estimated wattage in the top right, and from there, you will know the minimum wattage needed.

Whatever the wattage number they give you is, you can safely add another 100W to that and get a PSU close to that number.

You don’t want your computer to run very close to the maximum wattage of your PSU because if it goes over, that could lead to some severe issues.

Also, your PSU will function best at around 50% load. If you have too low or too high of a load on your PSU it won’t be as efficient which we will talk more about below.

If you plan on making lots of upgrades in the future, or especially if you plan on overclocking, it may even be better to go with a much higher wattage.

For a high-end build, 1000w is a safe bet that should cover the needs of all your parts and overclocking.

For a budget build, I would recommend going for 750w. Even though it is higher, you have lots of room to overclock and upgrade to higher wattage equipment.

Any GPU or CPU upgrades you do in the future will likely increase the wattage used by your build. This isn’t always true as sometimes parts can become more efficient and use less wattage than an inferior part.

For example, I currently have a 2070 super that runs at 215 watts. If I were to upgrade to a 3060 Ti, I would decrease the wattage used by 15 since the 3060 Ti only uses 200W.

However, if I were to make a significant upgrade that would substantially increase my performance, like going from the 2070 super to the 3080, I would increase the wattage used by 105 watts.

It all depends on what you currently have and what you are upgrading to in the future.

If you plan on doing major overclocking to get the absolute best performance out of your CPU or GPU, I would highly recommend going with a much higher watt PSU.

Overclocking CPUs can increase the wattage significantly, sometimes even by nearly double. Overclocking GPUs isn’t as bad; you typically see a 40 – 70 watt increase, but the exact amount will vary.

What’s The Difference Between Bronze, Silver, Gold, Platinum, And Titanium Rated PSUs?

These ratings are also known as the 80 plus system, measuring how efficient your PSU can run and use electricity.

Lower tiers in the 80 plus system like silver, bronze, or regular 80 plus are not going to be as efficient as Gold and above at processing power.

This will matter in your setup, and it isn’t just technical mumbo jumbo. The more efficient your PSU is at processing power means, the cooler it will run, and the less power draw it will have.

This also means the more efficient PSU you have, the longer it is going to last.

The 80 plus PSU rating system is voluntary, and to get any rating on this scale, the PSU must have at least a power factor of 0.9 at 100% load and at least 80% power efficiency at 20%, 50%, and 100% loads.

The higher the PSU efficiency in these tests, the better the rating will be in the metal-based ranking system.

To show an example of how the lowest tier looks, to get an 80 plus rating when your computer is supplied with 500 watts from the wall, your PSU must be able to process that and use 400 watts out of that.

The other 100 watts will turn into heat because the energy takes another form when not used.

A titanium level PSU will have 90% efficiency at a 100% load, meaning it will use 450 watts of the 500 watts supplied, only transferring 50 watts into heat and using the rest.

Stepping out of the very technical heavy jargon for a moment, this is precisely why you will also want a PSU with wattage that isn’t overkill for your build.

PSUs perform best when at 50% load and start to falter in performance at very high or very low loads.

This means that if you have an overkill PSU with way too much wattage, like a 1600W PSU for a build that uses 400W, you are hurting your PSU.

The same goes for getting a PSU with wattage that is too close to your actual usage. If you use 400W but get a 450 or 500W power supply, this will also hurt your PSU.

Ideally, you will get a PSU with wattage that your build will typically only use 50% of, so it will keep your PSU load in the most optimal range.

This is also excellent news for people on a budget because you can be benefiting your build by not overspending on an overkill PSU with too many watts.

Wrapping up this section, the higher the 80-plus rating, the more efficient your PSU will be at managing power.

This is good for your PSU because it can last longer, produce less heat, and use more of the power it is given instead of shedding large amounts into heat.

I recommend getting at least a Gold rated 80-plus PSU because they aren’t nearly as expensive as titanium, but they do have fantastic efficiency scores.

If you plan to get a higher rated PSU, make sure you get a wattage that makes sense.

Try to land your build around the 50% load spot to get the best efficiency out of your highly-rated PSU. This means if you run at 300W, try going for a 600W and so on.

Buy A Reliable Brand, Not The Cheapest Brand

Although it may be tempting to see that cheap price tag on some unnamed PSU that comes from no brand you’ve ever heard of, you should consider this.

The PSU is a centerpiece to any build that makes or breaks the components (quite literally). When faulty, PSUs can quickly short circuit and break several components or, even worse, start a fire.

They are also one of the less expensive places to invest in your build, and buying a good brand like EVGA or Corsair isn’t going to be all that much more costly than a no-name brand.

Many off-brand companies can lack quality, and a cheap PSU can likely die faster or have some other fault.

The point is, don’t get an off-brand PSU because they aren’t that expensive and are one of the only components that can single-handedly destroy your whole PC if it is faulty or fails.

Getting A Quiet PSU

Amongst the many essential things you should look for, there is a quiet PSU. PSUs have fans installed to make sure the heat can get pushed away, but you don’t want them to be loud like any component with fans.

Although no company will outwardly say if their PSU is very loud, you can check the reviews and typically get pretty honest input from an actual owner of the product.

Do PSU Rails Matter?

The rails in a PSU aren’t as important as they may have been in the past. These days single-rail PSUs are plenty safe, and in most situations, they will be protected by short circuit protection.

Short circuit protection is triggered when too much electricity is going down one set of connectors, and to avoid melting, it will shut down your PSU.

The benefit of 12 rail is that in some situations, that happens very rarely when the short circuit protection doesn’t work, the OCP will realize when too much voltage is coming down one rail and shut off the PSU.

It is a secondary measure of protection that does help in some rare scenarios; however, a single-rail PSU will be just fine in most cases.

In most situations, you don’t need to shop by rails, and there are more critical things like efficiency and wattage to worry about.

Wrap Up

PSUs are not a component you should cheap out on or put minimal effort into reading about when building your PC.

Since you are reading this article, you are probably a step ahead of most.

Fully modular, semi-modular, and non-modular PSUs are all differentiated by their different cord structures.

To reiterate, fully modular have no permanent cables, semi-modular have some permanent cables, and non-modular has all permanent cables.

Other than the visual benefits, you get better airflow using a semi or fully modular PSU, but they will scale in price as you become more modular.

For the lowest price, you can go non-modular; for the best balance, you can go semi-modular, and for the best airflow and cable management, you can use fully-modular.

Remember, if you decide to use modular PSUs, you cannot mix and match your favorite cables. You must use the cables that came with your PSU, and for any visual upgrades, use extension cables that are compatible with your PSU.

More critical to the performance of your computer is the 80 plus system. The 80 plus system is the metal-based ranking of how efficient your PSU is, and I recommend getting at least a gold-ranked PSU.

Of course, if you have the money in the budget and are creating the ultimate gaming PC, you can go all the way up to titanium for 90% efficiency.

You get less heat and more longevity with maybe some cents shaved off the power bill every month.

Don’t skimp on your PSU and we recommend getting at least a gold semi-modular PSU for mid-tier builds, and be sure to calculate your wattage!


I've been a PC gamer and builder for around 3 years now but my love for gaming spans many years all the way back to the Nintendo 64! Getting into PC gaming there was a lot of information that was hard to understand so I made it my mission to make PC gaming easy!

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