Server Rack Sizes-What’s the Difference?
When you decide to build a server, you must consider various factors and one of the most important ones is choosing the right mounting option. With tons of server rack dimensions, it is not as simple as designing the layout of your new apartment. However, understanding of basics enables you to make an informed decision. The key dimensions to consider are the depth, height, and width required by your server and accessories. Secondary factors such as security and thermal requirements are also involved, but they are more easily adjusted than the rack itself. So, let’s learn more about the key components.
Server Rack Height
The height of a rack is one of the most common ways to classify it. People frequently label their racks by height, such as “42U server racks,” where “U” stands for “rack units,” or “U-spaces,” which equals 1.75 inches.
A 48U (“7-foot rack”) is the standard height, with 42U being less common. This has become the “standard” because it is both spacious enough for growth and compact enough for easy access to equipment. There are also rack enclosures with 22U and 27U capacities. These are known as “half-rack” in the data center industry.
There are many non-standard sizes available as well, with open-frame racks being a good example. Because of their lighter weight and versatility, they can reach heights of up to 70U, or they can be as small as 5U.
Server Rack Depth
In contrast to height, server rack depth is commonly measured in inches and has a wider variety of sizes. They typically range in depth from 0 to 50 inches, with the most common sizes being 24 and 48 inches. A 24-inch rack is ideal for storing network equipment, AV equipment, patch panels, and other similar items.
A standard open-frame depth of 29 inches is compatible with many servers from Dell, HP, IBM, and Cisco. Any depth greater than that allows for larger equipment to be housed or extra space for cable management and other accessories. To help a shorter server achieve a perfect fit, you can use rails with adjustable mounting depths.
Server Rack Width
Since most equipment, especially servers, have a mounting width of 19 inches, the most common rack width is a standard 19 inches as well. Because of the standard 48-inch data center floor panel, many racks today have an exterior width of 24 inches (24 in. x 24 in.). Thus, a standard rack with a depth of 48 inches and a width of 24 inches makes it much easier to match your racks to your available floor space. A 24-inch depth rack keeps things simple because it only takes up one panel. Many racks have a 19-inch mounting width and a 24-inch exterior width. This provides space on the edge to manage cables, mount PDUs, or monitor equipment while optimizing floor space.
2-Post Racks Compared to 4-Post Racks
The rack type is the last factor to consider when comparing server rack sizes. A 2-post rack is made up of two vertical upright support beams, whereas a 4-post rack is made up of four. The mounting depth limitations of a two-post rack are determined by construction, and they are a good fit for lighter technology or accessories that require less depth. Switches, patch panels, routers, and telecommunications equipment are examples of this.
Because rails and shelves connect on all four posts, 4-post racks can carry significantly more weight than 2-post racks. This requires more mounting depth than two-post racks, but it makes up for it in sturdiness.
Despite strict depth and weight restrictions, 2-post racks can be as tall as a standard data center rack. The 2-post “half-racks” are approximately 24U in height, while full-sized racks are approximately 45U in height. Another reason they might be taller than expected is that some 2-post racks can be converted to 4-post racks using a caster kit.
Now that you understand which components contribute to the size of your server rack, you must consider your overall setup. A half-rack or smaller may be a good choice for a home or office with limited equipment. Unless you have very small equipment, a four-post rack should be used because it is designed to be mounted from both the front and back. Furthermore, mounting your equipment in a lockable, enclosed server rack will keep it protected.
It is best to overestimate the amount of space required in case you need to scale up over time.
To maintain proper airflow, an empty space can be filled with blanking panels. Data centers put a greater emphasis on the amount of floor space occupied, so finding server racks that are the exact dimensions of your floor panels simplifies the organization and installation process. Whatever size rack you decide is best for you, always keep your layout and limitations in mind first.
If you are interested in finding the right size server racks for your needs, reach out to Molnii experts for a consultation.