In
computing
Computing is any goal-oriented activity requiring, benefiting from, or creating computer, computing machinery. It includes the study and experimentation of algorithmic processes, and the development of both computer hardware, hardware and softw ...
, a pizza box is a style of
case design for
desktop computer
A desktop computer, often abbreviated as desktop, is a personal computer designed for regular use at a stationary location on or near a desk (as opposed to a portable computer) due to its size and power requirements. The most common configuratio ...
s or
network switch
A network switch (also called switching hub, bridging hub, Ethernet switch, and, by the IEEE, MAC bridge) is networking hardware that connects devices on a computer network by using packet switching to receive and forward data to the destinat ...
es. Pizza box cases tend to be wide and flat, normally in height, resembling
pizza delivery boxes and thus the name. This is in contrast to a
tower
A tower is a tall Nonbuilding structure, structure, taller than it is wide, often by a significant factor. Towers are distinguished from guyed mast, masts by their lack of guy-wires and are therefore, along with tall buildings, self-supporting ...
system, whose case height is much greater than the width and has an "upright" appearance. In modern usage, the term "pizza box" is normally reserved for very flat cases with height no more than , while those taller than 2 inches are referred to as ''desktop'' cases instead.
The common setup of a pizza box system is to have the
display monitor placed directly on top of the case, which serves as a
podium to elevate the monitor more towards the user's eye level, and to have other
peripheral
A peripheral device, or simply peripheral, is an auxiliary hardware device that a computer uses to transfer information externally. A peripheral is a hardware component that is accessible to and controlled by a computer but is not a core compo ...
s placed in front and alongside the case. Occasionally, the pizza box may be laid on its sides in a tower-like orientation.
History
With the tagline "Who just fit mainframe power in a pizza box?" in a 1991 advertisement for its
Aviion Unix
Unix (, ; trademarked as UNIX) is a family of multitasking, multi-user computer operating systems that derive from the original AT&T Unix, whose development started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, a ...
server products,
Data General
Data General Corporation was an early minicomputer firm formed in 1968. Three of the four founders were former employees of Digital Equipment Corporation (DEC).
Their first product, 1969's Data General Nova, was a 16-bit minicomputer intended to ...
was an early adopter of the expression in advertising,
returning to the theme on later occasions.
However, such usage was preceded by other occurrences of the expression in print, notably Time's 1989 coverage of
Sun Microsystems
Sun Microsystems, Inc., often known as Sun for short, was an American technology company that existed from 1982 to 2010 which developed and sold computers, computer components, software, and information technology services. Sun contributed sig ...
and its
SPARCstation 1 product.
The expression was reportedly already in use as early as 1987 to refer to the profile of an expansion unit for the
Digital Equipment Corporation
Digital Equipment Corporation (DEC ), using the trademark Digital, was a major American company in the computer industry from the 1960s to the 1990s. The company was co-founded by Ken Olsen and Harlan Anderson in 1957. Olsen was president until ...
VAXmate.
Most computers generally referred to as pizza box systems were high-end desktop systems such as Sun's
workstation
A workstation is a special computer designed for technical or computational science, scientific applications. Intended primarily to be used by a single user, they are commonly connected to a local area network and run multi-user operating syste ...
s of the 1990s. Other notable examples have been among the highest-performing desktop computers of their generations, including the
SGI Indy, the
NeXTstation
NeXTstation is a high-end workstation computer developed, manufactured, and sold by NeXT from 1990 until 1993. It runs the NeXTSTEP operating system. The system was designed to be a lower-cost option compared to the company's upscale product, t ...
, and the
Amiga 1000.

The pizza box form factor was also seen in budget and lower-end lines such as the
Macintosh LC family, which was popular in the education market.
The original SPARCstation 1 design included an expansion bus technology,
SBus, expressly designed for the form factor;
expansion card
In computing, an expansion card (also called an expansion board, adapter card, peripheral card or accessory card) is a printed circuit board that can be inserted into an electrical connector, or expansion slot (also referred to as a bus sl ...
s were small, especially in comparison to other expansion cards in use at the time such as
VMEbus
VMEbus (Versa Module Eurocard bus) is a computer bus standard physically based on Eurocard sizes.
History
In 1979, during development of the Motorola 68000 CPU, one of their engineers, Jack Kister, decided to set about creating a standar ...
, and were mounted horizontally instead of vertically.
PC-compatible computers in this type of case typically use the
PCI expansion bus and are usually either a) limited to one or two horizontally placed expansion cards or b) require special low-profile expansion cards, shorter than the PCI cards regular PCs use.
The density of computing power and stackability of pizza box systems also made them attractive for use in
data center
A data center is a building, a dedicated space within a building, or a group of buildings used to house computer systems and associated components, such as telecommunications and storage systems.
Since IT operations are crucial for busines ...
s. Systems originally designed for desktop use were placed on shelves inside of
19-inch rack
A 19-inch rack is a standardized frame or enclosure for mounting multiple electronic equipment modules. Each module has a front panel that is wide. The 19 inch dimension includes the edges or ''ears'' that protrude from each side of the ...
s, sometimes requiring that part of their cases be cut off for them to fit. Since the late 1990s, pizza boxes have been a common form factor in
office cubicles, schools, data centers or industrial applications, where desktop space, rack room and density are critical. Servers in this form factor, as well as higher-end
Ethernet switch
A network switch (also called switching hub, bridging hub, Ethernet switch, and, by the IEEE, MAC bridge) is networking hardware that connects devices on a computer network by using packet switching to receive and forward data to the destinat ...
es, are now designed for rack mounting.
Rack mount 1U computers come in all types of configurations and depths.
The pizza box form factor for smaller
personal systems and thin clients remains in use well into the 21st century, though it is increasingly being superseded by laptops,
nettop
A mini PC (or miniature PC, nettop, or Smart Micro PC) is a small-sized, inexpensive, low-power, Legacy free PC, legacy-free desktop computer, desktop computer designed for basic tasks such as Web navigation, web browsing, accessing web appl ...
s or
All-in-One PC
An all-in-one computer (also called an AIO or all-in-one PC) is a type of personal computer that integrates the computer components, such as the CPU, monitor, and speakers, into a single unit. It occupies a smaller footprint than a desktop co ...
designs that embed the already size-reduced computer onto the
keyboard or display monitor.
See also
*
Desktop form factor
References
External links
Pizza boxin the
Jargon File
The Jargon File is a glossary and usage dictionary of slang used by computer programmers. The original Jargon File was a collection of terms from technical cultures such as the MIT Computer Science and Artificial Intelligence Laboratory, MIT AI Lab ...
{{Computer sizes
Computer enclosure
Desktop computers
Networking hardware