Can SFX PSU Fit An ATX Case? (Check Before Installation)

Many beginner PC builders are confused about whether the SFX Power Supplies will fit inside an ATX PC Case or not.

Although the SFX PSUs are ideal for the SFF PC Cases, you can still install the SFX Power Supplies inside an ATX case, but you might need an adapter for it.

This article will talk about the whole topic, including the good and bad sides of putting an SFX PSU in an ATX case. It will also show you how to install the SFX PSU inside an ATX case.

What Is SFX PSU & ATX PC Case?

There are different kinds of Power Supplies, like ATX, SFX, TFX, and so on. SFX PSUs are smaller than ATX PSUs, while SFX PSUs are larger than TFX PSUs.

Here are the dimensions of all these PSU types-

PSU StandardSizes (Width, Height, Depth)
ATX PS/2 (ATX)150mm(W) x 86mm(H) x 140mm (D)
SFX125mm(W) x 63.5mm(H) x 100mm (D)
TFX85mm(W) x 64mm(H) x 175mm (D)

On the other hand, various types of PC cases are available in the market, including Full-Tower, Mid-Tower, Mini-Tower, and SFF PC Cases. Now, let’s look at the dimensions of these PSUs.

Case TypeDimensions (Sizes) (H x W x D)
Full Tower559 mm x 229 mm x 559 mm
Mid Tower457 mm x 190 mm x 457 mm
Mini Tower305-457 mm x 152-229 mm x 305-457 mm
SFF (Small Form Factor)305-381 mm x 152-178 mm x 305-381 mm

Now, you might be wondering about an ATX PC Case type; actually, there’s no specific thing called an ATX PC Case. ATX refers to a motherboard form factor, and the PC cases that support ATX motherboards are commonly referred to as ATX PC Cases.

In the PC building community, Mid-Tower PC Cases are often called ATX PC Cases. These mid-tower cases are made to fit ATX motherboards and other components. You can learn more about What PSU & motherboards are compatible with each other.

So, let me explain how you can install the SFX PSU inside a Mid-Tower (ATX) PC Case. But before we get into that, take a look at some of the advantages and disadvantages of using an SFX PSU inside an ATX PC Case.

Pros & Cons Of Using SFX PSU in ATX Case

There are several benefits of using an SFX PSU inside an ATX case, such as:

  • Airflow: If you use SFX PSU inside an ATX case, you will get more room to organize cables, and it will improve your computer’s airflow. This will also help your computer work better.
  • Noise: The SFX PSUs have smaller fans compared to the ATX PSUs, which makes the SFX PSUs quiet.  This can be a major benefit for users who want a quiet PC build.
  • Space: SFX PSUs are significantly smaller than ATX PSUs, which can free up space inside your case.

Challenges Of Putting SFX PSU Inside An ATX PC Case

Now, let’s talk about some problems you might face when putting a small SFX PSU into a big ATX case-

  • Compatibility: Not all ATX cases are compatible with SFX PSUs; you may require an SFX to ATX PSU adapter to install it. Buying the right & compatible adapter can be challenging.
  • Cable Length: The SFX PSUs have shorter cables than the ATX PSUs. This can be a problem if your case is large or your components are far from the PSU. You might need to buy cable extensions in order to reach all of your components.
  • Price: The price of the SFX PSUs is higher than the ATX PSUs. This is because SFX PSUs are more complex to manufacture and produce in smaller quantities.

SFX PSU In ATX Case: Installation Guide

To install an SFX PSU in an ATX case, you will need to use an SFX to ATX mounting bracket. This bracket will allow you to secure the SFX PSU to the case in the same way as an ATX PSU. You can buy the SFX to ATX mounting bracket from- Amazon.

Once you have the SFX to ATX mounting bracket, follow these steps to install your SFX PSU:

1. Firstly, you need to unbox the SFX to ATX mounting bracket adapter and it’s screws.

SFX to ATX PSU adapter

2. Next, you have to put the mounting adapter on the back of your SFX Power Supply and then use the screws to hold it in place.

Installing SFX to ATX PSU adapter

3. Once you connect the adapter to your Power Supply, place the Power Supply into your computer case and use the special screws that come with the case to make it secure.

4. After that, connect all the Power Supply cables to your motherboard and other components.

Additional Tips

  • If your ATX Power Supply has a PSU shroud, then you may need to remove it in order to install the SFX PSU.
  • If you’re putting a small SFX Power Supply into a big ATX case, you might need cable extensions. Make sure to use high-quality cable extensions that are compatible with your motherboard & PSU.
  • If you’re going to overclock your components, then you may want to consider using a larger SFX PSU with a higher output.

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Hi, I'm Pallab Mitra, the founder of this blog. I'm a computer enthusiast, and I'll be sharing my knowledge and expertise about PCs on this blog. Read More- About Me 

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