What Is a Modular Power Supply? Features, Advantages, and Disadvantages Explained

Power supply units can vary in cable management and ease of maintenance depending on the type of plug-in system they use.

A plug-in compatible power supply unit allows for the removal of unnecessary cables, making better use of internal space, improving the appearance, and most importantly, increasing work efficiency during assembly and maintenance.

There are some disadvantages, such as the risk of losing cables, but overall, the advantages of full plug-in and semi plug-in types are greater.

This article explains in detail the features, advantages, and disadvantages of each type.

It also covers basic knowledge about power supply unit standards and cables, as well as how to choose one from the perspective of performance and compatibility.

≫ Related article: How to Choose a Power Supply Unit for a Custom PC [Performance / Features / Compatibility]

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What is a Plug-in Power Supply Unit?

There are three types of plug-in systems for power supply units.

These types differ in how easy it is to assemble a custom PC and manage cables.

About 70% of power supply units on the market are non-modular (fixed cable) types, making them the most common.

Plug-in types (full/semi) make up the remaining 30%, so they are less common, but their advantages make them popular.

Full Plug-in (Modular Type)

(Reference: CORSAIR RM850e 850W )

A full plug-in (modular type) power supply unit is a power supply unit where all cables can be removed.

The biggest feature of this type is its flexibility, allowing the user to freely choose the type and number of cables to use.

For example, when building a PC, only the necessary cables can be selected and connected, which keeps the internal wiring neat and improves airflow.

Also, since there are no extra cables, the inside of the case looks clean, and assembly and maintenance are easier.

With the Custom PC Parts Estimate & Compatibility Check Tool, it is possible to search for power supply units that support plug-in systems, so be sure to use it.

Semi Plug-in (Semi-Modular Type)

(Reference: 玄人志向 KRPW-BK650W/85+ 650W Amazonで見る 楽天で見る Yahoo!ショッピングで見る )

A semi plug-in (semi-modular type) power supply unit is a power supply unit where all cables except for the main ones can be removed.

The main cables are those essential for running the PC, such as for the motherboard and CPU.

Since these cables are built directly into the power supply unit, it helps prevent loss or connection mistakes.

On the other hand, cables for storage devices or graphics cards can be selected and attached as needed, keeping the internal wiring neat.

This point is the same as with full plug-in types.

Non-Modular Type (Fixed Cable Type)

(Reference: Thermaltake PS-SPD-0500NPCW 500W )

A non-modular type (fixed cable type) power supply unit is a power supply unit where all cables are fixed to the main body.

This type is the most common among power supply units, and if only looking at power capacity and price, it offers the best cost performance.

However, unused cables can get in the way and make the inside of the PC case messy.

Therefore, there is the disadvantage of having to stuff extra cables into gaps in the PC case, which can be troublesome.

Advantages of Plug-in Compatible Power Supply Units

This section explains the advantages of plug-in compatible power supply units.

No Need to Worry About Where to Put Unused Cables

By using a plug-in compatible power supply unit, there is no need to worry about where to put unused cables.

With non-modular power supply units, unused cables had to be stuffed inside the case, but with plug-in types, only the necessary cables are connected, keeping the inside neat and organized.

There is usually a little space in front of the power supply unit to stuff extra cables, but it is often a tight fit.

It is best not to bend cables with too much force, but sometimes there is no choice.

Also, if the power supply unit is long or the PC case has a storage area nearby, space can be very tight, so it is best not to have unused cables.

With a plug-in compatible unit, especially when space around the power supply is limited, it is possible to assemble the PC smoothly without having to force extra cables into tight spaces.

Improved Work Efficiency for Custom PC Assembly and Maintenance

When assembling or maintaining a custom PC, just not having extra cables makes the work much easier.

This is the biggest advantage, and assembling with a non-modular power supply unit can be quite troublesome.

Power supply cables are often thick and stiff, so even if extra cables are moved aside by hand during assembly, they often get in the way again.

With a plug-in compatible power supply unit, only the necessary cables are connected, keeping the internal wiring neat and increasing workspace.

As a result, it is easier to install parts during assembly and to replace or clean parts during maintenance.

Furthermore, when considering future upgrades, it is easy to add only the necessary cables, allowing for flexible assembly.

Better Appearance Depending on the Case

With a plug-in compatible power supply unit, the inside of the PC case can look better.

Especially when using a PC case with a design that shows the inside, such as tempered glass, cable routing and organization become important.

Basically, with a non-modular power supply unit, cables are stored in a place not visible from the tempered glass (the back side), so there is not much difference between non-modular and plug-in types.

However, some PC cases do not allow for back-side cable management or have visible cables, so in such cases, a plug-in compatible power supply unit will look better.

Little Price Difference Compared to Non-Modular Types Despite the Advantages

Plug-in compatible power supply units have little price difference compared to non-modular types.

Some may think that the removable cable mechanism would make them more expensive.

While they are a bit more expensive, the difference is usually only a few hundred to a thousand yen, so considering the ease of assembly and maintenance and not having to stuff extra cables, they are a good deal.

With less wiring work and easy maintenance or replacement, they are very convenient for installation and future upgrades.

Despite this convenience, the price is only slightly higher than non-modular types, so the overall cost performance of plug-in compatible power supply units is high.

Therefore, for users who want to keep initial costs down but also consider future maintenance, plug-in type power supply units are an attractive choice.

Disadvantages of Plug-in Compatible Power Supply Units

This section explains the disadvantages of plug-in compatible power supply units.

Although there are some disadvantages, overall they are minor and not much of a concern.

Risk of Losing Cables

When using a plug-in compatible power supply unit, there is an unavoidable risk of losing cables.

Since only the necessary cables are connected, unused cables must be stored separately.

However, it is possible to lose track of stored cables or forget where they were put.

Especially in environments with many devices, cables can get scattered and lost easily.

Therefore, it is important to pay attention to cable management and consider proper storage methods.

That said, for custom PC storage, putting unused parts and screws in the large cardboard box from the PC case after assembly usually prevents loss.

Slightly Lower Power Delivery Due to Contact Resistance

With plug-in compatible power supply units, there are more contact points since cables connect not only to the parts but also to the power supply unit itself.

Therefore, contact resistance increases, and in theory, this can cause a slight decrease in power delivery.

However, in reality, this effect is very small and does not affect PC performance.

If stable power could not be supplied because of this, plug-in type power supply units would not exist in the first place.

Also, power supply units are made to strict quality standards and are designed to minimize power loss due to contact resistance.

Therefore, while this can be listed as a disadvantage, in practice there is almost no need to worry.

Summary: For Work Efficiency, Appearance, and Ease of Use, Semi and Full Plug-in Types Are Recommended!

This article explained the advantages and disadvantages of plug-in power supply units.

Here is a summary of the key points.

With a plug-in compatible power supply unit, there is no need to worry about unnecessary cables, making custom PC assembly and maintenance easier, and depending on the PC case, the appearance is also cleaner.

Also, the price is often not much different from non-modular types.

There are disadvantages such as the risk of losing cables, but considering the ease of assembly and other advantages, plug-in compatible power supply units are definitely worth considering.

If work efficiency, appearance, and ease of use are important, semi and full plug-in power supply units are absolutely recommended.

It also covers basic knowledge about power supply unit standards and cables, as well as how to choose one from the perspective of performance and compatibility.

≫ Related article: How to Choose a Power Supply Unit for a Custom PC [Performance / Features / Compatibility]

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PC Parts Estimation & Compatibility Check Tool

Automatically checks each component you need when selecting parts for a custom-built PC—perfect for beginners.