What Are Small Form Factor PCs?

Computers the size of a shoe or pizza box work great in tight spaces

Mac Mini
Apple Inc.

The earliest computers filled an entire room. By the early 1980s, they were small enough to fit on a desktop. With the introduction of new features such as solid-state drives and tiny drive formats like M.2 cards, systems can get even smaller—to the size of a few decks of playing cards.

The Earliest Small-Form-Factor PCs

Slim PCs were the earliest style of small-form-factor system. They were desktop systems that removed some of the bulk by reducing space for full-sized expansion cards. This design cut desktops height or width by half. Since that time, they have reduced their size even more. They still tend to have PCI-Express expansion slots but have half-height slots that require specific expansion cards that are difficult to find. Some may use a riser card system that rotates the card 90-degrees to fit a full-size card but often at the expense of the number of cards it holds.

Businesses prefer standard computers that don't have a lot of expansion capabilities, because the companies depreciate the cost of the computers over their lifespan or they lease them. Once a system has reached its "lifespan" it is replaced by a new, updated computer. Because there is no need for expansion, an integrated system such as a slim PC makes perfect sense. The computers don't have to be top-of-the-line when it comes to components since most business computing limits to low-intensity word processing, spreadsheets, and corporate communications.

Expandable SFF PCs Cubes

cube pc
©MAINGEAR

The cube small-form-factor systems gained in popularity primarily from the enthusiast and PC gamer marketplace. They still fit all the normal desktop computer components but unlike slim PCs, they offer a limited number of full-sized expansion slots. It is this expansion ability that has really driven the cube computers by the enthusiasts.

Prior to the rise of network gaming and LAN parties—where people bring their PCs to a single location to network them together—manufacturers never saw the demand for small-sized systems that included an advanced graphics capability. Integrated graphics are more than sufficient for corporate computing tasks. Trying to run a brand-new 3D game title on one of these systems was like watching a slideshow. Gamers install graphics cards with the latest technology, a task made possible by cube-style small-form-factor PCs.

The Latest Small-Form-Factor PCs

2014 Mac mini
Apple, Inc.

The latest in the small-form-factor PCs is the mini PC. These are very small systems that are about the size of a large-format paperback book or several DVD movie cases stacked. They gained in popularity with the release of the Apple Mac Mini and newer desktop computer releases by various PC manufacturers. The systems can get as small as they do because they are based on laptop components and lack a display, keyboard, and mouse to help reduce the size. Power supplies also reside outside of the computer systems. Apart from perhaps some memory chips, these devices aren't internally upgradable.

Advantages of SFF PCs

The primary advantage of SFF PCs is the size. Because of their reduced size and components, use less power than a normal desktop. Since they only have space for one or two hard drives and maybe two expansion cards, there is very little demand for power outside of the primary processor.

Disadvantages of SFF PCs

The biggest disadvantage is the lack of expansion. To save space, many internal expansion slots and memory slots are removed. Generally, a system will only have two memory slots compared to four in a normal desktop system. The lack of expansion cards means that the user can only fit one or two cards into the computer—if any.

With the development of USB 3.0 and the introduction of USB 3.1, expansion isn't as much of a barrier as it once was.

The other consideration is cost. Even though the systems have fewer parts than a desktop system, the cost for them tend to be a bit higher than for a laptop with similar specifications, and when you add monitors and peripherals, the price sometimes significantly outweighs desktop machines.