Form Factors and Computer Cases

In this article, we will explain what a computer form factor is and why it matters. We will also explain the different types of motherboards and how this can affect the case of the computer you choose.

With ever-advancing technology, the number of PC cases available on the market is always expanding. Whilst a refurbished desktop is the perfect solution for reducing your carbon footprint and helping prevent IT waste, you still need to understand the type and style of the computer you need.

The computer case not only affects the aesthetic of your workstation but also plays an important role in the performance of your PC as it has a heavy influence on which components can be used.

Form FactorsForm Factors

What is a Form Factor?

Here at Stone Refurb, we have often been asked ‘what is a motherboard form factor?. In regard to computers, the form factor refers to the size, shape, and specifications of hardware or hardware components.

The form factor design is shaped by the components that are found within the larger hardware unit. One example of the various types of form factors is the difference between a tower PC and a laptop. Although the components of each are often the same, they are shaped, arranged, and attached in different ways.

In simple terms, the form factor is essentially a rough guide to the size of the case. There are no set dimensions but each type normally fits within a range of measurements and will house a specific size of the motherboard.

What Different Motherboard Sizes Are There?

The motherboard is one of the most important parts of a PC. A high-quality motherboard provides suitable system stability and ties together each of the components, allowing elements such as the CPU or hard drive to interact.
There are a variety of motherboard sizes available on the market. The type of motherboard you need will depend on how you want to use your computer, however, it is important to remember that the case used for the computer must match the motherboard form factor.
The motherboard’s form factor has a standardisation of dimensions used and fits into three main types and sizes, from the largest to the smallest:

  • ATX
    These are the biggest and allow for the largest number of expansion slots and ports, so are ideal for upgrading. They will only fit in the bigger cases.
  • Micro ATX
    These are the most common type of motherboard size and are ideal for most users, including gamers. These are often put in full tower cases as well as mid-sized cases because they are of good value and are common to find.
  • Mini ATX
    There are fewer slots than the larger Motherboards so adding more card is difficult but they still have the full functionality of larger boards.

Most motherboards have standard locations for power supply, placement of mounting holes, and the number and positioning of ports and slots for connecting components and peripherals but they can differ across manufacturers.

PC Case Sizes

In order to house the various types of motherboards, there are a variety of different PC case sizes. From the traditional tower PC to discreet miniature desktops, you can be sure to find a computer that will match your aesthetic and workstyle.
Here are the most common types of PC cases, along with a run-through of the pros and cons of each device:

Full Tower – ATX Motherboard

Full-tower cases are the biggest cases available, with a height normally of 24” (60 cm) or more. The number of internal drive bays inside these cases can be between 6 and 10 so there is lots of room for expansion. They can have up to 11 peripheral components interconnect (PCI) slots.

Mid Tower - ATX or Micro ATX Motherboards

The next case size down is the mid-tower case. These provide the sweet spot between upgradability and size. Mid-tower cases are the most widely used computer cases and are normally about 18” to 24” high (45cm to 60cm) and they usually contain 2 to 4 internal drive bays for hard drive additions and a similar number of external bays (for CD or DVD drives and similar). These have up to 7 PCI slots.

Mini Tower - Micro ATX or Mini ATX Motherboards

Mini towers usually have 1 or sometimes 2 internal drive bays, to add extra hard drives. The mini-cases normally stand at a height of 12” to 18” (30cm to 45cm). Expandability is a problem with these cases, as the room can be limited. These have up to 3 PCI slots.

Desktop - Micro ATX or Mini ATX Motherboards

Desktop cases are simply tower cases turned on their side but they are slightly slimmer, meaning they could not fit a full-size graphics card (GPU) inside. They can hold a monitor on top of the case to free up space elsewhere. These have up to 4 PCI slots.

Small Form Factor (SFF) - Micro ATX or Mini ATX Motherboards

SFF cases are slightly smaller than Desktop cases but serve the same purpose of saving space. They are the same in thickness but are about three-quarters of the size. Most SSF cases have easy access to the inside with a pull handle on the side or top (depending on how you have it positioned) so you don’t have to mess about with any screws. These usually have up to 2 PCI slots.

Ultra-Small Form Factor (USFF) – Bespoke Motherboards

USFF cases are custom cases that are designed to minimize the spatial volume of a desktop computer. These computers usually take laptop size hard drives and memory. Most USFF computers use highly integrated motherboards containing many on-board peripherals, reducing the need for expansion cards so are often very difficult to upgrade. These smaller form factors have more restricted airflow, so can get quite warm.

Micro – Bespoke Motherboards

Micro PCs are the smallest there is. These PCs are mainly used to attach to the back of monitors to save the most desk space. Like USFF PCs, these also take laptop-sized hard drives and memory. Most can also have a Wi-Fi card fitted but this does vary, so a USB Wi-Fi adapter is an option. Other upgrades such as expansion cards are very limited and they do not have space for an optical drive.

Final Thoughts

Whether you are looking for a refurbished desktop or want a refurbished laptop, the style of the computer you chose will be affected by the type of motherboard you need. From creating animations to playing computer games, there are a variety of different sizes of motherboard form factors available on the market.

If you are unsure which size computer case or motherboard is right for your usage, get in touch with our friendly team of experts today! With 30 years in the IT industry, they are more than happy to discuss your options and find your ideal fit. 

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