What is a Server Rack? (Easy Guide for a Complex Topic)


Server room | Racks within a server room at CERN | Torkild Retvedt | Flickr

What is a server rack?

Rugged computers are available in a variety of configurations to support a wide range of military, industrial, and commercial applications.

The distinctive rack server, on the other hand, is the most common type of server available today.

These slidable, hot-swappable, rugged computers are perfect for harsh environments and programs that emphasize space conservation, scalability, upgradability, and expandability.

In this blog post, we’ll go over how rack servers work, the various sizes of rack servers and server racks, and how to pick the best of both for your program or application.

A rack server also recognized as a rack mount server, rack-mounted server, or rack mount computer, or rack mountable, is a computer that is designed to be installed in a rectangular structure known as a server rack.

The benefits of a server rack involve better space conservation for rack servers, increased scalability, extra air flow when combined with a cooling system, and easiness of regular computer maintenance and diagnostics due to their design, which allows technicians and operators to easily slide rack servers in and out of them.

What is the purpose of a rack server?

Rack servers, like every other server, provide clients with data and specific services. They’re common in data centres with dozens, if not hundreds, of server racks and rack cabinets.

Rugged rack servers are frequently found supporting military and industrial applications in the areas.

These dependable, high-powered machines are stress-tested to withstand harsh conditions such as extremely high pressures and temperatures, vibration during transport or operation, and moisture in parts of the world where atmospheric moisture is prevalent.

They are certified to military and industrial standards such as MIL-STD-810H, MIL-STD-461, CE, FCC, or DO-160.

Rack servers are frequently found in military programs, either inside compact and sturdy MIL-STD-810-certified rack server cases or supporting an embedded computing application.

How does a rack server function

How do rack servers work?

Rack servers can easily slide in and out of a server rack mechanically.

This feature is useful because it allows system administrators, technicians, and operators to diagnose technical issues and hot-swap parts without having to shut down and disassemble the entire system.

Such a feature is essential for mission-critical programs and applications, where prolonged downtime could result in financial loss, bodily harm, or even death.

Computationally, the performance, resources, and services of a rack server are tailored to the requirements of a program or application.

To help on-site computation and gain access to critical resources and intellect, a remote military installation in the desert may require a high-powered rack database, email, web, file, or application server, whereas a commercial warehouse or industrial oil rig may run a series of rack servers that process and store data from security cameras, assembly line computers, or fracking control mechanisms.

How wide is a rack mountable server?

Since most rack servers are 19 inches wide, they can fit in the standard 19-inch server rack configuration. Industry server racks are typically 19 inches wide, but they are also available in 23 and 24 inch widths.

Server racks and rack servers are typically measured in rack units. 1.75 inches equals one rack unit (U).

The method of evaluating how many rack mount servers a server rack can hold is known as server racking.

When purchasing for rack mount computers, the rack unit measurement is frequently expressed as [number]U.

Multiply the rack unit number by 1.75 inches to get the height of your server or rack in inches.

A rack server, for instance, may have a 1U rack height, which equates to 1.75 inches of vertical space; thus, a rack must have at least 1U rack dimensions or at least 1.75 inches of vertical space.

Take into account a rack server with 4U rack dimensions, or 7 inches of vertical space. A normal small server rack with a 4U rack height can hold one 4U rack server, which is a perfect fit for a 7-inch server, but it can also hold:

  • Four 1U rack servers, each requiring 1.75 inches of vertical space.
  • Two 2U rack servers, each requiring 3.5 inches of vertical space.
  • One 3U rack server and one 1U rack server, each taking up 5.25 and 1.75 inches of vertical space.

Each 2U rack server and 2 1U rack servers, with the 2U server requiring 3.5 inches of vertical space but each 1U server requiring 1.75 inches of vertical space.

Normally, taller server racks exist than a 4U rack.

Other widely known rack heights are 42U and 44U racks, which correspond to 73.5 and 77 inches of usable space, respectively.

You could fit a variety of different-sized rack servers into these racks, or you could simply use twenty-one 2U rack servers for the 42U rack and twenty-two 2U rack servers for the 44U rack.

However, there are racks that are even taller than the 44U. Rack Solutions claims its $969 70U Open Frame Server Rack is the “likely tallest server rack in the world,” meeting all Electronics Industries Alliance (EIA) standards.

Whats the difference between a tower server a rack server and a blade server

What’s the difference between a tower, a rack, and a blade server?

Due to high scalability, flexibility, upgradability, and capacity to support compute-intensive software, rack mount servers are the most widely used servers in the army, industrial, and commercial programs and applications, but the tower and blade servers also appear occasionally.

A tower server is a single, upright computer that looks like a desktop PC tower. It is commonly limited to small businesses and other commercial settings.

Tower servers are self-contained, which means they cannot be inserted into server racks, and they are taller and bulkier than rack mount and blade servers.

Tower servers aren’t usually expensive, but they take up a huge amount of space, making scaling difficult.

Furthermore, many tower servers necessitate the disassembly of the entire system in order to repair, replace, or upgrade components.

A blade server is a narrow, lightweight, modular computer that is the size and functionality of a nightstand drawer.

Blade servers are also known as rack servers because they are frequently housed inside racks in what are known as blade enclosures or blade systems.

Blade servers, like rack servers, are slidable and hot-swappable, and they’re much smaller than both tower and rack servers.

The blade server will be very useful for programs and projects that emphasise space conservation and high processing power, such as web hosting.

Blade servers use less power than the tower and rack mount servers because their chassis is usually the only source of power for the system.

They also use less power cables than their counterparts, but their expandability is severely limited due to their small size.

Blade servers, tower servers, and rack servers can support a high level of processing power, a large amount of storage, and PCIe expansion.

What to consider when purchasing a server rack?

The server rack you select will be determined by the requirements of your business, program, or operation.

You’ll need to figure out how many servers you’ll need for your project, as well as the height (RUs) and width of your server rack. To determine the proper rack size, make a comparison of these measurements to the height and width of your servers.

Which rack server is the most suitable

Which rack server is the most suitable?

The best rack server for your program or operation will be determined by a number of factors, including size, weight, and power (SWaP), as well as scalability, expandability, and upgradability.

In fact, the larger the server, the more expansion and storage options you have; however, keep in mind that as more components are added, the server becomes heavier and may require more power.

Let’s look at a few examples.

What’s the difference between a 1U and a 2U rack server?

A 1U rack server can strongly support the same CPUs and RAM as a 2U server; but even so, due to its small size, it has less space for PCIe slots and storage.

Slots and storage on almost any rack server, although, can be grown using a PCIe expansion kit or JBOD enclosure.

What’s the difference between a 3U, 4U, and 5U rack server?

A 3U rack server, like the 1U and 2U rack servers, will have fewer PCIe slots and storage options than a 4U or 5U rack server.

A 5U rack server has a lot of power. A 5000 Series Rugged Server, for example, can natively support up to 18 PCIe Gen 3 slots, 48 front-access/hot-swap SATA 6 Gb/s drives, 4 internal, fixed 2.5″ 6 Gb/s SATA drives, and up to two SlimLine Optical drives. When combined with a PCIe expansion kit and/or JBOD, you have a formidable machine.


We can assist you in determining not only the size, type, and number of rack servers you require, but we also provide integrated rack solutions for programmes and applications that require multiple rack servers in a single rack.

Frequently Asked Questions

What can I make of a server rack?

A server rack houses and organizes critical IT systems that can be configured to meet a variety of needs. It is enclosed to ensure security and is commonly referred to as a server rack cabinet.

What are the benefits of using a rack server?

A server rack provides better space conservation for rack servers, increased scalability, maximised air flow when combined with a cooling system, and the easiness of regular computer maintenance and diagnostics.

How many different kinds of racks are there?

Racks for servers (aka cabinet racks, equipment racks, 4Post racks) Racks with an open frame (aka 4post racks) Transport racks for 2Post (also known as relay racks or telco racks).

About the Author
Daniel Luke
Daniel is a WordPress web designer with vast experience working with various WordPress themes that allows him to compare and contrast different themes, understand the strengths and weaknesses to develop factual, real-world reviews.

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