View source for Engineering:Computer case

{{short description|Enclosure that contains most of the computer hardware}}
[[File:Gabinete99.jpg|alt=ATX desktop case|thumb|An ATX case. The motherboard (microATX) is in a horizontal position at the top, and the peripheral connectors go at the panel located at the rear of the case and USB ports at the top. The fans are also at the rear and front. The power supply is on the bottom rear.]]
A '''computer case''', also known as a '''computer chassis''', is the [[Engineering:Housing (engineering)|enclosure]] that contains most of the [[Computer hardware|hardware]] of a [[Engineering:Personal computer|personal computer]]. The components housed inside the case (such as the CPU, [[Engineering:Motherboard|motherboard]], [[Computer memory|memory]], [[Mass storage|mass storage]] devices, power supply unit and various [[Engineering:Expansion card|expansion card]]s) are referred as the ''internal'' hardware, while hardware outside the case (typically [[Engineering:Electrical cable|cable]]-linked or plug-and-play devices such as the [[Engineering:Computer monitor|display]], speakers, [[Computer keyboard|keyboard]], [[Computer mouse|mouse]] and [[Engineering:USB flash drive|USB flash drive]]s) are known as ''[[Engineering:Peripheral|peripheral]]s''.

Conventional computer cases are fully enclosed, with small holes (mostly in the back panel) that allow [[Biology:Heating, ventilation, and air conditioning|ventilation]] and cutout openings that provide access to [[Engineering:Electrical connector#Plug and socket connectors|plugs/sockets]] (back) and [[Removable media|removable media]] [[Engineering:Drive bay|drive bay]]s (front). The structural frame ([[Engineering:Chassis|chassis]]) of a case is usually constructed from rigid [[Chemistry:Metal|metal]]s such as steel (often SECC — steel, electrogalvanized, cold-rolled, coil) and [[Chemistry:Aluminium alloy|aluminium alloy]], with hardpoints and [[Engineering:Through hole|through hole]]s for mounting internal hardware, [[Engineering:Computer fan|case fan]]s/coolers and for organizing [[Cable management|cable management]]. The external case panels, at least one of which are removable, cover the chassis from the front, sides and top to shield the internal components from physical intrusion and dust collection, and are typically made from painted metallic and/or [[Chemistry:Plastic|plastic]] material, while other materials such as [[Engineering:Mesh|mesh]], [[Physics:Tempered glass|tempered glass]], [[Chemistry:Poly(methyl methacrylate)|acrylic]], [[Biology:Wood|wood]] and even Lego bricks have appeared in many modern commercial or [[Engineering:Case modding|home-built cases]]. In recent years, ''open frame'' or ''open air'' cases that are only partly enclosed (with freer ventilation and thus theoretically better [[Computer cooling|cooling]]) have become available in the premium gaming PC market.

==Sizes and terminology==
[[File:Computer case - Full Tower.jpg|150px|thumb|right|A full tower case. Accessories shown include: a [[Engineering:Computer fan control|fan controller]], a DVD burner, and a USB [[Memory card reader|memory card reader]].]]
Cases can come in many different sizes and shapes, which are usually determined by the [[Engineering:Form factor (design)|form factor]] of the [[Engineering:Motherboard|motherboard]] since it is physically the largest hardware component in most computers. Consequently, personal computer form factors typically specify only the ''internal'' dimensions and layout of the case. Form factors for rack-mounted and [[Blade server|blade server]]s may include precise ''external'' dimensions as well since these cases must themselves fit in specific enclosures.

For example, a case designed for an ATX motherboard and power supply unit (PSU) may take on several external forms such as a vertical [[Engineering:Computer tower|''tower'']] (designed to sit on the floor, height > width), a flat [[Engineering:Desktop computer|''desktop'']] (height < width) or ''[[Engineering:Pizza box form factor|pizza box]]'' (height ≤ {{cvt|5|cm|0|disp=or}}) designed to sit on the desk under the computer's [[Engineering:Computer monitor|monitor]]). Full-size tower cases are typically larger in volume than desktop cases, with more room for [[Engineering:Drive bay|drive bay]]s, [[Engineering:Expansion slot|expansion slot]]s, and custom or all-in-one (AIO) water cooling solutions. Desktop cases—and ''mini-tower'' cases under about {{convert|18|in|cm|abbr=on|order=flip}} high—are popular in business environments where space is at a premium.<ref>{{cite web|url=http://www.pcguide.com/ref/case/styles.htm |title=Reference Guide – Case – Styles}}</ref>
[[File:Stripped-computer-case.JPG|alt=An empty computer case|thumb|330x330px|An empty computer case]]
Currently, the most popular form factor for desktop computers is ATX,{{citation needed|date=August 2017}} although microATX and small form factors have also become very popular for a variety of uses. In the high-end segment, the unofficial and loosely defined XL-ATX specification appeared around 2009. It extends the length of the mainboard to accommodate four graphics cards with dual-slot coolers. Some XL-ATX mainboards increase the mainboard's width as well, to allow more space for the CPU, Memory PWM, and in some cases, a second CPU socket. While the market share of these exotic high-end mainboards is very low, almost all high-end cases and many mainstream cases support XL-ATX (10 expansion slots). As of 2018, no major motherboard manufacturer has made an XL-ATX board for several years. E-ATX is similar to XL-ATX in that it is larger than ATX and is also loosely defined. Unlike XL-ATX, E-ATX motherboards and cases are still in production (as of 2020), and support quad-channel memory across 8 slots of ram, up to 4 PCI-e expansion slots for up to 4 double slot graphics cards and a single CPU such as the AMD Ryzen Threadripper 3990X.<ref>{{Cite web|url=https://www.gamersnexus.net/guides/3566-e-atx-is-a-lie-vs-xl-atx-eeb-ceb|title="E-ATX" is a Lie: XL-ATX, E-ATX, ATX, EEB, and SSI-CEB}}</ref><ref>{{Cite web|url=https://www.zdnet.com/google-amp/article/heres-what-you-need-to-run-amds-new-64-core128-thread-ryzen-threadripper-3990x/|title=Here's what you need to run AMD's new 64-core/128-thread Ryzen Threadripper 3990X &#124; ZDNet|website=[[ZDNet]] }}</ref><ref>{{Cite web|url=https://www.anandtech.com/show/15483/amd-threadripper-3990x-review|title=The 64 Core Threadripper 3990X CPU Review: In the Midst of Chaos, AMD Seeks Opportunity}}</ref><ref>{{Cite web|url=https://www.anandtech.com/show/15121/the-amd-trx40-motherboard-overview-|title=The AMD TRX40 Motherboard Overview: 12 New Motherboards Analyzed}}</ref><ref>{{Cite web|url=https://www.anandtech.com/show/15121/the-amd-trx40-motherboard-overview-/14|title=The AMD TRX40 Motherboard Overview: 12 New Motherboards Analyzed}}</ref> Companies like [[Company:In Win Development|In Win Development]], [[Company:Shuttle Inc.|Shuttle Inc.]] and AOpen originally popularized small cases, for which FlexATX was the most common{{Dubious|date=November 2009}} motherboard size. As of 2010 Mini ITX has widely replaced FlexATX as the most common small form factor mainboard standard. The latest mini ITX mainboards from [[Company:Asus|Asus]], [[Gigabyte]], [[Company:Micro-Star International|MSI]], [[Company:ASRock|ASRock]], Zotac and [[Company:Foxconn|Foxconn]] offer the same feature set as full size mainboards. High-end mini ITX mainboards support standard desktop CPUs, use standard memory DIMM sockets, and mostly feature a full-size PCI-E 16× slot with support for the fastest graphics cards, although some instead use a PCI, or PCIe slot of fewer than 16 lanes. This allows customers to build a fully-fledged high-end computer in a significantly smaller case. [[Company:Apple Inc.|Apple Inc.]] has also produced the [[Engineering:Mac Mini|Mac Mini]] computer, which is similar in size to a standard CD-ROM drive, and many manufacturers offer mini-ITX cases of similar size for low-wattage CPUs with integrated graphics.


Tower cases are often categorized as mini-tower, midi-tower, mid-tower, or full-tower. The terms are subjective and inconsistently defined by different manufacturers.

''Full tower cases'' are typically {{convert|56|cm|in|0|abbr=on}} or more in height and intended to stand on the floor. They can have anywhere from six to ten externally accessible drive bays. The full tower case was originally developed to house [[File server|file server]]s which would typically be tasked with serving data from expensive CD-ROM databases that held more data than the hard drives commonly available at the time. Hence, many full tower cases include locking doors and other physical security features to prevent theft of the discs. However, as computing technology moves from [[Floppy disk|floppy disk]]s and [[CD-ROM]]s to large capacity hard drives, USB flash drives, and network-based solutions, more recent full tower cases typically only have none, one, or two external bays for CD drives, with the internal bays moved elsewhere in the case to improve airflow. Today, full tower cases are commonly used by enthusiasts as showpiece display cases with custom water cooling, lighting, and tempered glass (replacing acrylic).<ref>{{Cite web|url=https://www.kitguru.net/components/leo-waldock/corsair-obsidian-1000d-watercooled-dual-system-part-2/|title = Corsair Obsidian 1000D Watercooled Dual System – Part 2 &#124; KitGuru}}</ref><ref>{{Cite web|url=https://www.anandtech.com/show/12762/corsair-launches-obsidian-1000d-supertower-case|title=When Size Matters: Corsair Launches Obsidian 1000D Super-Tower Case}}</ref><ref>{{Cite web|url=https://www.guru3d.com/news-story/size-does-matter-meet-the-corsair-obsidian-1000d-super-tower-pc-case.html|title = Size Does Matter ? Meet the Corsair Obsidian 1000D Super Tower PC Case}}</ref> They may also hold two computers (as is the case with the Corsair 1000D) and dual power supplies (Corsair 900D).<ref>{{Cite web|url=https://www.storagereview.com/review/corsair-obsidian-series-900d-case-review|title = Corsair Obsidian Series 900D Case Review|date = 19 April 2013}}</ref><ref>{{Cite web|url=https://www.tomshardware.com/reviews/obsidian-900d-case-review,3482-7.html|title = Corsair Obsidian 900D Review: Making Room for High-End Gear|date = 23 April 2013}}</ref>

''Mid-tower cases'' are smaller, about {{convert|46|cm|in|0|abbr=on}} high with two to four external bays. They may also hold two computers.<ref>{{Cite web|url=https://www.gamersnexus.net/hwreviews/3379-phanteks-evolv-x-case-review-dual-system-thermals|title = Phanteks Evolv X Case Review: Dual-System, Thermals, & Quality}}</ref>

A ''mini-tower'' case will typically have only one or two external bays.<ref>{{cite web|url=http://www.overclockers.com/coolermaster-cosmos-ii-ultra-tower-case-review |title=CoolerMaster Cosmos II Ultra Tower Case Review|work=Overclockers|date=January 27, 2012|access-date=September 28, 2013}}</ref>

The marketing term ''midi-tower'' sometimes refers to cases smaller than mid-tower but larger than mini-tower, typically with two to three external bays.<ref>{{cite book |last=Gilster |first=Ron |date=2000 |url=https://books.google.com/books?id=b2tYAAAAYAAJ&q=%22midi-tower%22+%22mini+tower%22+%22mid+tower%22 |title=PC Technician Black Book |publisher=Coriolis |page=359 |isbn=9781576108086 |via=Google Books}}</ref> Other times the term may be synonymous with ''mid-tower''.<ref>{{cite book |last=Rosch |first=Winn L. |date=2003 |url=https://books.google.com/books?id=S90OaKQ-IzMC&dq=%22midi-tower%22+%22in+between%22&pg=PA1065 |title=Winn L. Rosch Hardware Bible |publisher=Que |page=1065 |isbn=9780789728593 |via=Google Books}}</ref>

==Layout==
Computer cases usually include sheet metal enclosures for a power supply unit and drive bays, as well as a rear panel that can accommodate [[Engineering:Peripheral|peripheral]] connectors protruding from the motherboard and [[Engineering:Expansion slot|expansion slot]]s. Most cases also have a power button or switch, a [[Reset button|reset button]], and [[Engineering:LED|LED]]s to indicate power, hard drive activity, and network activity in some models. Some cases include built-in I/O ports (such as [[Engineering:USB|USB]] and headphone ports) on the front of the case. Such a case will also (normally) include the wires needed to connect these ports, switches, and indicators to the motherboard.<ref>{{cite web |last1=Ryley |first1=Nick |title=What Are Front Panel Connectors? |url=https://thepcgeekz.com/what-are-front-panel-connectors/ |website=ThePCGeekz}}</ref>

===Major component locations===
* The [[Engineering:Motherboard|motherboard]] is usually screwed to the case along its largest face, which could be the bottom or the side of the case depending on the form factor and orientation.
* Form factors such as ATX provide a back panel with cut-out holes to expose I/O ports provided by integrated peripherals, as well as [[Engineering:Expansion slot|expansion slot]]s which may optionally expose additional ports provided by [[Engineering:Expansion card|expansion card]]s. Many larger ATX cases can also be used with motherboards of other form factors.
* The power supply unit mounting point differs from case to case, but the most commonly used locations (both at the rear of the case) and their advantages/disadvantages are:
**The top of the case, usually allowing the PSU's built-in fan to act as an auxiliary exhaust fan but causes the PSU to be fed air heated by the internal components of the case, thus causing PSU efficiency and lifespan degradation.
**The bottom of the case, with an (often filtered) vent in the bottom of the case allowing the PSU to draw cool air from the outside.
*Regardless of the mounting position, the PSU will usually be attached to the case with four [[Engineering:Screw|screw]]s to support its weight.
* Most cases include [[Engineering:Drive bay|drive bay]]s on the front of the case; a typical ATX case includes 5.25", 3.5" and 2.5" bays. In modern computers, the 5.25" bays are used for optical drives, the 3.5" bays are used for hard drives and [[Card reader|card reader]]s, and the 2.5" bays are used for solid-state drives.
* Buttons and LEDs are typically located on the front of the case; some cases include additional I/O ports, temperature, and processor speed monitors in the same area.
* Vents are often found on the front, back, top, left side panel, and sometimes on the right-side panel of the case. Regardless of their placement, their purpose is either to let cool air into the case or to let hot air out. Larger vents usually allow [[Engineering:Computer fan|cooling fans]] to be mounted via surrounding threaded screw holes. Newer cases include mountings for larger 120 mm or 140 mm cooling fans for quieter operation than the 80 mm fans formerly common.
* An I/O template, or I/O plate, fits around the motherboard's back panel of external ports. Sometimes provided by the case manufacturer, it is often replaced by the one that comes with the motherboard.

===Internal access===
Accessing the interior components of a modern ATX tower case is done by removing the side panels. Looking front-to-back, accessing the motherboard, PSU, drive bays, and most case fan installation points are done by removing the left side panel.
Removing the right-side panel is done less often to access the space behind the motherboard mounting plate. This space is devoted to cable management, as cables routed in front of the motherboard may disrupt the flow of air within the case causing increased temperatures.<ref>{{Citation|last=Linus Tech Tips|title=Cable Management – Does it impact cooling performance? At all?...|date=2016-02-08|url=https://www.youtube.com/watch?v=YDCMMf-_ASE |archive-url=https://ghostarchive.org/varchive/youtube/20211222/YDCMMf-_ASE |archive-date=2021-12-22 |url-status=live|access-date=2018-08-11}}{{cbignore}}</ref> BTX, an uncontemporary standard, has the main side panel on the right side as opposed to the left. Some upside-down designed ATX cases are also accessed by removing the right-side panel door.

Alternatively, the case may have a single large U-shaped cover that saddles the chassis. This was ubiquitous in AT tower cases.

To prevent the buildup of performance-degrading dust within the case, many models feature dust filters in front of the air intake fans. While the exact method of accessing the front filters depends on the case model, it usually requires the removal of the entire front panel. Removal of the front panel itself may or may not require the removal of one or both of the side panels. If there is any doubt, consult the user's manual if possible.

Traditionally, most computer cases required [[Engineering:Computer case screws|computer case screws]] to hold components and panels in place (i.e. motherboard, PSU, drives, and expansion cards). From the early 2000s onwards there is a trend towards tool-less cases, in which components are held together with snap-in plastic rails, thumbscrews, and other methods that do not require tools; this facilitates quick assembly and modification of computer hardware and is also cheaper to manufacture.

==Appearance==
{{further|Engineering:Case modding}}
Throughout the 1990s, most computer cases had simple rectangular shapes, and were often painted beige or [[White|white]] with little attention given to the visual design. [[Beige box]] designs are still found on a large number of budget computers assembled from generic components. These class of machines are now known as [[Engineering:White box (computer hardware)|white box computers]], albeit at this point the cases are generally colored black or silver instead of beige. More modern computer cases include a much wider range of variation in shape, color, form factor, and materials, such as brushed aluminium and/or tempered glass which are offered with more expensive cases.

''Case modding'' is the artistic styling of computer cases, often to draw attention to the use of advanced or unusual components. Since the early 2000s, some cases have included clear side panels or acrylic windows so that users can look inside while it is operating. Modded cases may also include colored internal lighting, custom paint, or liquid cooling systems. Some hobbyists build custom cases from raw materials like aluminum, steel, [[Chemistry:Styrofoam|styrofoam]], acrylic, or wood.

Historically, cases used CCFL lighting<ref>{{Cite web|url=https://books.google.com/books?id=xwIAAAAAMBAJ&q=computer+case+ccfl&pg=PT23|title = Maximum PC|date = October 2004}}</ref> and eventually single color LEDs as strips or in fans to illuminate their interior; modern cases use RGB LED lighting instead, often incorporated into case fans. To improve airflow while allowing RGB fans to be visible, many cases as of 2020 use metal meshes, without any external bays.<ref>{{Cite web|url=https://www.gamersnexus.net/guides/3534-gn-awards-show|title=GN Awards Show: Best & Worst PC Cases of 2019 (Thermals, Quality, Noise)}}</ref> Many include a PSU shroud and vertical gpu mounts. Some used to include holes to support external water cooling radiators.<ref>{{Cite web|url=https://www.gamersnexus.net/hwreviews/3579-phanteks-p300a-case-review-benchmark-vs-p400a#!/ccomment|title=Phanteks P300A Case Review vs. P400A, NR600, & More: Thermals, Noise, Fans}}</ref><ref>{{Cite web|url=https://www.gamersnexus.net/news/1282-nzxt-h440-case-specs-psu-shroud|title=NZXT H440 Case Specs – Includes PSU Shroud; Video Preview & Hands-On}}</ref><ref>{{Cite web|url=https://custompc.raspberrypi.org/articles/the-pros-and-cons-of-vertical-graphics-card-mounts|title = The Pros and Cons of Vertical Graphics Card Mounts}}</ref><ref>{{Cite web|url=https://www.gamersnexus.net/guides/3324-fact-check-cablemod-vertical-gpu-thermals-vs-stock-h500m|title=Fact-Check: CableMod's Vertical GPU Thermals vs. Stock Case}}</ref><ref>{{Cite web|url=https://books.google.com/books?id=cgIAAAAAMBAJ&q=pc+case+external+radiator&pg=PA38|title=Maximum PC|date=July 2006}}</ref><ref>{{Cite web|url=https://books.google.com/books?id=RQIAAAAAMBAJ&q=pc+case+external+radiator&pg=PA52|title=Maximum PC|date=August 2006}}</ref> Cases with side windows may have side fans (on the window) as well, although it is uncommon for cases with glass windows to have side fans.<ref>{{Cite web|url=https://www.gamersnexus.net/guides/692-how-many-case-fans-should-you-have|title = The Basics of Case Fan Placement – How Many Fans and Where?}}</ref>

===Case manufacturers===
Prominent after-market case manufacturers include [[Company:Antec|Antec]], [http://www.bitfenix.com/ BitFenix], [[Company:Cooler Master|Cooler Master]], [[Company:Corsair Gaming|Corsair]], [[Company:Fractal Design|Fractal Design]], [[Company:In Win Development|In Win Development]], Lian Li, NZXT Corp., [[Company:Phanteks|Phanteks]], Rosewill, and [[Company:Thermaltake|Thermaltake]], (DIY PC)

==Intrusion detection==
Some computer cases include a biased switch ([[Engineering:Push-button|push-button]]) which connects to the motherboard.  When the case is opened, the switch position changes, and the system records this change.  The system's [[Firmware|firmware]] or [[BIOS]] may be configured to report this event the next time it is powered on.

This physical intrusion detection system may help computer owners detect tampering with their computers. However, most such systems are quite simple in construction; a knowledgeable intruder can open the case or modify its contents without triggering the switch.

In the past, many tower cases intended to house [[File server|file server]]s featured a locking door covering the external drive bays. This was a security feature intended to prevent the theft of the [[CD-ROM]] discs the drives would be holding. At the time, CD-ROM capacity was larger than the hard disks available, and many business-critical databases were distributed on this media. These databases were often very expensive or held proprietary data, and hence would be likely targets for casual theft.

==Gallery==
<gallery perrow="8" caption="Computer cases">
ATX computer case - left - 2018-05-18.jpg|Interior of a 2018 ATX computer tower
ATX computer case - back - 2018-03-18.jpg|Back of an ATX computer tower
ATX computer case - right - 2018-05-12.jpg|Right part of an ATX computer case with the fixing of the CPU at top right
ATX computer case - front - 2018-05-12.jpg|Front of an ATX computer case
ATX computer case - facade buttons - 2018-05-12.jpg|Facade buttons of an ATX computer case
Macpro.png|Mac Pro tower case. Note the two barely visible front intake fans.
Modified-pc-case.png|Enthusiast case featuring translucent panel [[Engineering:Case modding|casemod]]
SWTPC6800 open.jpg|[[Engineering:SWTPC 6800|SWTPC 6800]] case with SS-50 and SS-30 buses—an early hobbyist machine
Paris servers DSC00190.jpg|Three of the Wikimedia servers in [[Rack unit|1U]] rackmount cases
Home theater PC front with keyboard.jpg|[[Company:Antec|Antec]] Fusion V2 [[Home theater PC|home theater PC]] case with [[Engineering:Vacuum fluorescent display|VFD display]], volume control and some [[Engineering:Computer port (hardware)|ports]] on front
80486-Desktop-PC.jpg|8-slot Baby AT form factor case
Power Macintosh 9600 350.jpg|Power Mac tower case
NeXTcube.jpg|NeXT Cube
SGI-indigo-front.jpg|SGI Indigo tower case
Silicon Graphics O2 Plus.jpg|SGI O2 tower case
IBM PC 5150 no monitor.jpg|[[Engineering:IBM Personal Computer|IBM Personal Computer]]
IBM 5150 Casing.jpg|IBM Personal Computer 5150 bare 5-slot case
Ibm px xt color.jpg|[[Engineering:IBM Personal Computer XT|IBM Personal Computer XT]]
IBM PS2 MCA Model 55 SX, front.jpg|IBM Personal System/2 Model 55SX
IBM PS2 MCA Model 55 SX, internal components overview.jpg|IBM Personal System/2 Model 55SX
Mac mini mid2010 front.jpg|The 2010 [[Engineering:Mac Mini|Mac Mini]] from Apple
</gallery>

==See also==
* List of computer hardware
* [[3D printing|3D printing]]
* [[Company:List of computer hardware manufacturers|List of computer hardware manufacturers]]
* [[Software:Novena (computing platform)|Novena]]
* [[Engineering:Thermally Advantaged Chassis|Thermally Advantaged Chassis]]
* VIA OpenBook open case design standard.
* [[Computer cooling]]
* [[Engineering:Computer fan|Computer fan]]

==References==
{{Reflist}}

==External links==
* [https://web.archive.org/web/20081108034536/http://www.formfactors.org/formfactor.asp Chassis Form Factors]

{{Basic computer components}}

[[Category:Computer enclosure| ]]

{{Sourceattribution|Computer case}}