Difference Between 2-Post vs. 4-Post Rack | Enconnex

2 and 4-post racks are essential IT infrastructure components and have been for many years. Generally used for enterprise network applications, they can be found in IT closets, MDFs, and IDFs of businesses across the globe. 

There are a number of differences between 2-post and 4-post racks. Each has characteristics that make it more appropriate for specific use cases.  It’s important to understand them all to decide which is best for your environment or application.

2-Post Racks

2-post racks have two vertical supports attached to a wide metal footplate that may be bolted to the floor for stability. 2-post racks are also called telco racks or relay racks because they were traditionally used by telecom carriers. They’ve been in existence for over a century.

Equipment isn’t installed on mounting rails — it is attached to the posts and supported in a cantilever fashion. The manufacturer will specify a maximum mounting depth to minimize the risk that the rack will tip over. Because 2-post racks can’t be easily enclosed, they are best used in secure rooms where access is controlled.

Key characteristics of 2-post vs. 4-post racks include:

• Lower cost. 2-post racks are less expensive than 4-post racks — depending on the model, they can cost as little as half as much as a comparable 4-post rack.
• Smaller size.  Because 2-post racks take up less space than 4-post racks, they are ideal for wiring closets and data centers with limited floor space.
• Limited capacity. 2-post racks have lower load capacities. They are designed for lighter-weight equipment, such as networking gear and patch panels, and generally cannot support fully loaded servers or equipment with extended depth.
• Easy assembly. 2-post racks can be assembled more easily than 4-post racks and cabinets.
• Easy access. Administrators can easily access the equipment in an open 2-post rack.
• Different material. 2-post racks are generally made from extruded aluminum and have tapped rack-unit holes for equipment mounting.

4-Post Racks

4-post racks have four vertical supports attached to a rectangular base and held in place by a rectangular “roof.” Equipment in a 4-post rack is mounted on rails, and the rack must be able to accommodate the depth of the equipment, plus room for cabling and airflow.

Key characteristics of 4-post vs. 2-post racks include:

• Larger capacity. 4-post racks have higher load ratings, can support significantly more weight than 2-post racks, and provide a more stable environment for heavy equipment and equipment with extended depth.
• Greater protection. Although not standard, 4-post racks can be outfitted with side panels, doors, and a top panel to limit access to the equipment housed within the rack.
• Simplified planning. 4-post racks can accommodate virtually all types of IT equipment, making it easier to adapt to future needs and growth.
• Improved cable management. Cabling run inside a 4-post rack has less risk of being damaged or becoming disconnected.
• More options. 4-post racks can be customized with handy options such as fixed and sliding shelves and door locks.
• Different material. 4-post racks are made from aluminum, steel, or a combination of both materials. Tapped or square mounting holes (for cage nuts) are common on 4-posts.

Although there are many differences between the two types of rack, both can accommodate vertical cable managers, and both are typically shipped in flat-packed/unassembled form to assemble on-site.

How to Choose the Right Solution for Your Data Center

A well-built rack has a long service life, so it’s essential to consider both present and future needs when selecting. The experts at Enconnex have extensive experience in data center and IT infrastructure design, with expertise in data center racks and cabinets. They can help you choose the right rack based on cost, technology requirements, and other factors to help you maximize the return on your investment. Explore Enconnex racks and cabinets for sale, and contact us today to discuss your requirements.