PC Case Buyers Guide

Your PC’s case is a more than just a box to house all the components, modern cases offer so much more, with a huge variety of shapes, sizes, colours and materials to choose from.

Why the right case is important for your PC

It’s important to choose the right case for your PC because components such as motherboards, CPU coolers, power supplies and drives come in a wide variety of sizes, and also have their own cooling requirements. This buyers guide will demystify this process, teaching you all you need to know when selecting a new PC case.

Motherboard Compatibility

The first and most important decision to get right is choosing a case that is big enough to house the motherboard. The good news is that whatever brand of case or motherboard you look at, all manufacturers design their components according to a common set of industry standards. All you need to do is ensure that the case and motherboard are both the same standard. The most common standard for mid-tower and full tower size PCs is ATX. The other standards are Micro-ATX and Mini-ITX, both of which are smaller than ATX, and finally the enormous E-ATX SSI-EEB standard. The diagram below illustrates the dimensions of the most common motherboard sizes.

170 x 170 mm 244 x 244 mm 305 x 244 mm 305 x 330 mm

Although a larger motherboard will require a larger case, there’s nothing to stop you installing a small motherboard in an oversized case. This could be beneficial as larger cases do provide some benefits such as more cooling options and additional drive bays. It all depends on how much space you have available for your PC and your other requirements.

PSU Compatibility

It’s also important to make sure you choose a case that is right for your PSU. Like motherboards, PSUs come in a variety of standard sizes as shown below.




Please note, there is no standard for micro-ATX PSUs, so a micro-ATX case will normally use an ATX PSU. One word of caution, some extremely high wattage PSUs, 1200W and above, are much longer than the 140mm of the ATX standard and so many require a case with an extra-long PSU bay. If in doubt check the Specification tab on the product page of the case on the Scan website.

Cooling Capabilities

A well-designed case does a lot more than keep dust away from your precious PC components. It will also channel air through your PC, keeping everything cool and quiet - much better than having a PC sat out in the open. While every case is designed to air-cool a PC, some cases have additional fan mounts and space inside making them more suitable for water-cooled PCs. Depending on your how you intend to cool your PC this is what you need to look out for.

The best cases for air-cooling

Even the cheapest case will include a fan mount or two and normally some fans. If you’re building an entry-level PC a single exhaust fan at the back or top of the case is normally sufficient, but high-end PCs will require more fans, with some sucking cool air into the case and others exhausting hot air out of the case. Make sure you choose a case with sufficient fan mounts, ideally for 120 or 140mm fans as these are more efficient than smaller fans.

The best case manufacturers, such as Corsair, show on their product pages how many fans the case supports.
If you’re intending on using a particularly large CPU heatsink then make sure the case has sufficient space to house the cooler, the best way to do this is on the product page of the cooler on the Scan website and clicking on the Specifications tab and check its height versus the width of the case. Always leave room to spare as some of the width of the case will be taken up by the motherboard and its standoffs.

The best cases for hydrocoolers

If you’re going to buy a CPU or GPU with an all-in-one hydrocooler it’s critical you choose a case that has the right number of compatible radiator mounts. Hydrocoolers come in three main size groups, 120/140mm hydrocoolers with a single fan, 240/280mm hydrocoolers with two fans and 360/420mm hydrocoolers with three fans. You can check what each case supports on the product page of the case on the Scan website and clicking on the Specifications tab which will list what size radiators the case supports.

The best cases for custom water-cooled PCs

Custom water-cooling is lot more complex than a CPU or GPU hydrocooler because you not only need to find a case that has the right number of compatible radiator mounts but also plenty of room for the pump, reservoir and tubing. Some cases provide dedicated mounting points for these components, but often your only option is to bolt or screw the pump and reservoir into any spare space you can find.

For custom water-cooled PCs the larger the case the better as it’ll have more space for the components and be easier to work inside while you’re building your custom water-cooled PC.

Drive bays

The next thing you need to think about is what drives your PC will have and how more you may add in the future. For example, a lot of modern cases don’t have external drive bays anymore, so if you want a DVD or Blu-ray drive then make sure you check that case has a 5.25in external bay. For hard drives and SSDs, you will need to check how many internal 3.5in and 2.5in internal drive bays there are.

My PC Has
DVD or Blu-ray drives need a 5.25in external bay Hard drives need a 3.5in internal bay SSDs need a 2.5in internal bay

Pro tip: if you run out of space in your PC, you can buy drive bay adaptors that enable you to install smaller drives into large bays. Once again, you can check what each case supports on the product page of the case on the Scan website and clicking on the Specifications tab which will list how many drive bays and their sizes the case supports.


In addition to the usual power and reset button, all cases have some external I/O ports (Input Output) to help you connect devices to it, such as cameras and external drives. This saves you having to reach around behind the PC to the rear I/O ports every time you want to use one of these devices.

The most popular combination is a handful of large USB A ports plus audio connections for headsets. However, some cases are beginning to include the smaller, more modern and faster USB Type C ports, so if you need one of these its well worth checking the Specifications tab of the case on the Scan website. pay extra attention to which version of USB the case and motherboard support, as there are multiple versions in the market.

Windows and RGB Lighting

These days PC cases are available in a huge variety of colours, and many also have one or more transparent panels so you can ogle all the gorgeous hardware inside. At the cheaper end of the market these transparent panels are made from acrylic, but at the higher end they are made from tempered glass. We strongly recommend choosing a case made from tempered glass as it much harder wearing than acrylic and less susceptible to scratches.

Many cases also include RGB fans as standard, though you can always add more RGB fans and lighting strips according to your own tastes.

If you want a case with a side window to view the inner workings of your PC then it’s worth thinking about orientation. The reason for this that the vast majority of mid tower and full tower PC cases are designed to be viewed through a window in the left side panel. This is because they mount the motherboard on the right side of the case. As a result, if your desk arrangement is such that you can only have the PC on your left it’s important to choose a reverse case which mounts the motherboard on the left and the window on the right. A tiny number of cases even allow you to choose the motherboard orientation yourself.

Quiet Cases

While every case will muffle the sound of your PC to some extent, some cases are specially engineered to be as quiet as possible. The quietest cases are fitted a layer of foam on the outer panels that absorbs sound vibrations and plates to cover up unneeded fan mounts. Just beware that you need to strike the right balance between making your PC as quiet as possible while ensuring if its adequately cooled, so it can’t be completely sealed box.

Some cases also include fan controllers with a dial or switch on the front panel to adjust fan speed. However, we’d recommend avoiding these sorts of fan controllers and using the motherboard BIOS or a Windows application to control the fan speed instead as you’ll get far more control and can create a custom profile unique to your PC.

The best PC cases

There you have it, everything you need to know when choosing a new PC case. We hope you've found this buyers guide helpful. Don't hesitate to contact one of our friendly advisors for more advice if you still have questions on how to select the perfect case. If you’re all set to go we recommend checking out these cases from these top brands.