FormFactor

Formfactor, or form factor, refers to the physical size, shape, and layout of a product or component. It specifies external dimensions, mounting points, connector arrangements, and often thermal and power characteristics. The form factor governs how devices fit inside enclosures, how heat is managed, how components are assembled, and how upgrades or replacements are performed. It is a key consideration in design, manufacturing, and procurement.

In computing and consumer electronics, form factors are used to ensure interoperability and proper fit. Common motherboard form factors include ATX, microATX, and Mini-ITX, which define dimensions, mounting hole locations, and I/O layout. Computer cases are categorized by form factor to match motherboard size and cooling requirements, such as full-tower, mid-tower, or small form factor designs. Storage devices follow form factors like 3.5-inch and 2.5-inch for drives, while memory modules use DIMM or SO-DIMM form factors. Power supplies also have form factors (for example ATX and SFX) that determine connector types and mounting compatibility.

Form factor considerations extend beyond PCs to mobile devices, industrial equipment, and consumer electronics, where enclosure geometry, battery placement, and module arrangement affect durability and usability. Standards bodies and industry groups publish guidelines to promote compatibility, while manufacturers may adopt proprietary form factors to differentiate products or optimize specific use cases. The form factor concept also influences product ecosystems, accessory support, and repairability.

As technologies evolve, form factors balance performance, efficiency, portability, and manufacturability. Designers weigh size constraints against thermal limits, power delivery, and user needs to create practical, interoperable products.