science

Small form factor PC

Small form factor PC is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Small form factor PC rather than just read about it. In short: Small form factor (SFF) is a classification of desktop computers and for some of their components, chassis and motherboard, to indicate that they are designed in accordance with one of smaller standard form factors, intended to minimize the volume and area occupied by the computer, compared to the standard ATX form factor. For comparison purposes, the volume of an SFF case is usually measured in litres.

Key takeaways

Small form factor PC belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Small form factor PC to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Small form factor PC from memory before moving on to harder problems.

Reference excerpt

Small form factor (SFF) is a classification of desktop computers and for some of their components, chassis and motherboard, to indicate that they are designed in accordance with one of smaller standard form factors, intended to minimize the volume and area occupied by the computer, compared to the standard ATX form factor. For comparison purposes, the volume of an SFF case is usually measured in litres. SFFs are available in a variety of sizes and shapes, including shoeboxes, cubes, and book-sized PCs. Their smaller and often lighter construction has made them popular as home theater PCs and as gaming computers for attending LAN parties. Manufacturers also emphasize the aesthetic and ergonomic design of SFFs since users are more likely to place them on top of a desk or carry them around. Advancements in technology combined with a reduced size enables a powerful computer to be a smaller size. Small form factor designs do not include computing devices that have traditionally been small, such as embedded or mobile systems. However, "small form factor" lacks a normative definition and is consequently open to interpretation and misuse. Manufacturers often provide definitions that serve the interests of their products. According to marketing strategy, one manufacturer may decide to mark their product as "small form factor" while other manufacturers are using different marketing name (such as "Minitower", "Microtower" or "Desktop") for personal computers of similar or even smaller footprint.

History

The initialism SFF originally stood for "Shuttle Form Factor," describing shoebox-sized personal computers with two expansion slots. The meaning of SFF evolved to include other, similar PC designs from brands such as AOpen and First International Computer, with the word "Small" replacing the word "Shuttle". The term SFF is used in contrast with terms for larger systems such as "mini-towers" and "desktops."

Features Small form factor computers are generally designed to support the same features as modern desktop computers, but in a smaller space. Most accept standard x86 microprocessors, standard dual in-line memory modules (DIMMs), standard 8.9 cm (3.5 in) hard disks, and standard 13.3 cm (5.2 in) optical drives. However, the small size of SFF cases may limit expansion options; many commercial offerings provide only one 8.9 cm (3.5 in) drive bay and one or two 13.3 cm (5.2 in) external bays. Standard central processing unit (CPU) heatsinks do not always fit inside an SFF computer, so some manufacturers provide custom cooling systems. Though limited to one or two expansion cards, a few have the space for 3⁄4-length cards such as the GeForce GTX-295. Most SFF computers use highly integrated motherboards containing many on-board peripherals, reducing the need for expansion cards. By 2020, many SFF PC cases no longer included any expansion bays larger than 2.5 inches (large enough to accommodate SATA SSDs), due to the declining popularity of optical disc drives and 3.5-inch hard drives in the consumer space.

Enthusiast community and crowdfunding Crowdfunding and availability of rapid prototyping tools has enabled the production of several mini-ITX cases focusing on efficient organization of commercial computer components into small volumes including the Ncase M1, Ghost S1, DAN A4-SFX, and Thor Zone MJOLNIR. Communities of enthusiasts and reviewers develop and promote enhanced SFF assembly, maintenance, and performance criteria. 3D printing and laser cutting have enabled customization and one-unit production by both manufacturers like Lazer3D and individual users with access to the relevant equipment.

Types The many different types of SFFs are categorized loosely by their shape and size. The types below are available as of 2013.

Cubic (shoebox) Many SFF computers have a cubic shape. Smaller models are typically sold as barebone computers, including a case, motherboard, and power supply designed to fit together. The motherboard lies flat against the base of the case. Upgrade options may be limited by the non-standard motherboards, cramped interior space, and power and airflow concerns. The Power Mac G4 Cube, released in 2000, and the Shuttle XPC are good examples of this design. Micro-Star International (MSI) and Asus produce similar designs. The Xi3 Modular Computer is an example of a cube computer with a little more upgrade possibilities. Shuttle has adapted several of its XPC models (some 5-series and most later) to alternately accept mini-ITX motherboards. The base of the XPC is provided with mounting points which accommodate both "Shuttle form factor" (ShFF) and mini-ITX motherboards. In order to accommodate mini-ITX motherboards, two of the ShFF mounting points are simply relocated (the remaining mini-ITX mounting points are in common with the remaining ShFF mounting points). A "standard" ShFF motherboard is 20.6 cm (8.1 in) wide by 27.3 cm (10.7 in) deep, with the I/O shield and the two PCI slots being located in common with mini-ITX motherboards. Most ShFF systems utilize Shuttle's proprietary heat pipe (liquid cooling) system, "Integrated Cooling Engine" (ICE), for the processor, although several also feature heat pipe cooling for the voltage regulator and/or the chip set (Northbridge). When an ShFF system is upgraded to a mini-ITX motherboard, an Intel or compatible processor fan must replace the ICE cooler. The ShFF's ICE computer fan is so designed that it may be repurposed as a case fan when the case is upgraded to mini-ITX use. When so upgraded, the repurposed fan would be connected to the motherboard's case fan connector (3-pin) while the new CPU fan would be connected to the motherboard's CPU fan connector (4-pin). AOpen produced a stackable S120 case, allowing the user to stack up to four components vertically or horizontally. These layers can be for add-on cards, optical drives, and hard drives, using either internal power supplies or external AC adapter power sources. After the S120, AOpen made more small form factor cases for systems with Micro ATX and Mini-ITX.

Sandwich

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Illustrations

Worked examples

Example 1 — a first encounter with Small form factor PC

Start with the simplest possible case. Write down what Small form factor PC claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Small form factor PC before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Small form factor PC ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Small form factor PC

In research: Small form factor PC appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Small form factor PC in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Small form factor PC is common in secondary-school and first-year university syllabi. It links to neighbouring topics Motherboard form factors, so understanding it makes those chapters shorter.
In everyday life: Look for Small form factor PC outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Small form factor PC in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Small form factor PC means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Small form factor PC out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Small form factor PC in simple terms?

Why does Small form factor PC matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Small form factor PC?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Small form factor PC.