Power Supply Form Factors Explained!

When it comes to selecting the perfect components for your dream gaming PC, it can seem a little daunting. Especially when you have to consider the size of your hardware, not just the type of hardware you need.

But fear not – that’s where our team of PC experts at Overclockers UK comes in! We’ve compiled this handy guide on everything you need to know about different power supply (PSU) form factors. Sit back, grab a brew, some biscuits, and let’s get to it.

What is the Power Supply (PSU)?

Just as the name suggests, the power supply is what supplies the stream of power to all of the components in your gaming PC. Every PSU comes with different voltages and efficiency ratings.

If you want more information about power supplies, check out our ultimate guide to PSUs.

Learn More

What are the Different Form Factors?

The standard PSU form factors are:

ATX
TFX
SFX
SFX-L

ATX:

The most widely available form factor, ATX PS/2 can fit into most PC chassis, from micro-ATX and above, and come fully equipped with comprehensive cooling solutions. A combination of intelligent fan bearing technology and integrated fans helps to ensure your gaming PC stays cool and quiet! As ATX is most commonly used by gamers and enthusiasts alike, these PSUs often come in varying styles, colours, and some even include additional RGB lighting for an added flair to your PC.

ATX PSUs are typically 150 x 86 x 140mm, but the dimensions do vary depending on your model. Therefore, we recommend you check the product guide that came with your chosen ATX PSU.

Silverstone SST-DA1650-G 1650W 80 Plus Gold Modular PSU:

1650W
80 Plus Gold rating
Modular
ATX form factor

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SFX:

If you are creating your dream gaming PC but require one that saves space but is packing in performance – you will want to invest in an SFX PSU. These PSUs may be small, but still offer up to 800W, and are therefore perfect for a high-powered small gaming set-up. SFX PSUs will effortlessly fit into any size of PC chassis, even a mini-ITX or micro-ATX. What’s more, since they are designed to save on space, SFX PSUs are typically fully modular. This means you can pick and choose what cables to use, and reduce unsightly cable clutter.

A standard SFX power supply measures 125 x 100 x 63mm. However, this does differ between models so it’s best to consult with the manufacturer’s specifications for exact measurements.

Lian Li SP750W 750W 80 Plus Gold SFX Modular PSU:

750W
80 Plus Gold rating
Modular
SFX form factor

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SFX-L:

Designed to still save on space, SFX-L power supplies can still fit into smaller cases, such as a micro-ATX. Similar to SFX, SFX-L PSUs are typically fully or semi modular, allowing you to only use the cables you need. This means you can become an expert at cable management and easily achieve the sleek, tidy PC of your dreams!

SFX-L PSUs are typically 125 x 130 x 63.5mm, but similar to ATX and SFX, this can vary depending on your chosen model. As such, we recommend you double check your power supply’s manual or product page for more details.

be quiet! SFX-L Power 500W 80 Plus Gold Modular SFX-L PSU:

5000W
80 Plus Platinum rating
Modular
SFX-L form factor

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TFX:

TFX power supplies are thin, low wattage PSUs that are not widely used for gaming or content creation. However, instead, they are perfect for those looking to create their own mini or home-media PC set-up. A standard TFX PSU measures 175 x 85 x 65mm. However, this does differ between models so it’s best to consult with the manufacturer’s specifications for exact measurements.

be quiet! 300W 80 Plus Gold TFX 3 PSU:

80 Plus Gold Rated
300W
TFX form factor
Integrated 80mm fan

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ATX 3.0

ATX 3.0 PSUs have been designed to expertly handle the power demands of modern-day gaming hardware such as the NVIDIA RTX 40 Series and AMD Ryzen 9000 Series. These PSUs feature a 16-pin PCIe 5.0 12VHPWR power connector and can deliver up to 600W, from one single cable!

A typical ATX 3.0 measures 150 x 86 x 140mm. However, the exact dimensions of your PSU depend on the model and manufacturer. This is why we suggest you check the specifications of the power supply prior to purchase.