Server Types: Rack Server vs. Blade Server vs. Tower Server

Today, there are three major types of servers applied in data centers, namely rack servers, blade servers, and tower servers. These three types of servers have their advantages and disadvantages. They also have different effects on the performance, space, and scalability of the data centers. What should be the server solutions for different application scenarios? Here let us know about them: rack server vs. blade server vs. tower server.

What Are They and How Do They Work?

The following introduces the definition, form and function of rack servers, blade servers and tower servers. These three network servers have their unique features in terms of form factor and performance.

Rack Server

Rack servers are designed according to unified standards, usually installed in racks, and can be placed in metal enclosures with stacking for easy management. The racks connect to each server's monitor, keyboard, and mouse, allowing IT staff to access and configure resources. In general, rack dimensions are 1.75 inches high and 19 inches wide. The size of the rack server is adapted to the vertical multiple of the rack unit, and its height may be 1U, 4U, 10U, or higher.

Compared with blade servers and tower servers, the space occupied by rack servers is in the middle of the balance. The expansion of the internal space is still relatively limited, and only 1-2 PCI expansion slots are allowed. Large data centers may use rack-mounted servers to save space and facilitate the management, but must pay attention to heat dissipation.

Blade Server

Blade servers are similar to rack servers, but smaller in size, containing only modular circuit boards such as the server CPU, internal memory, and network control. However, some blade servers have storage drives installed and can be used for network storage, such as SAN or NAS devices.

Usually, blade servers are placed in server cabinets that can contain more servers, which saves a lot of space. So blade servers are often used when dealing with data clusters. However, their intensive work also generates a lot of heat, so good cooling is needed to keep them running efficiently.

Tower Server

Tower servers are self-contained rack-configured servers consisting of minimal components and software that supports customization for specific mission needs. It has no premium graphics card, premium RAM, or other parts while offering custom upgrades that allow users to configure it as a general-purpose server, web server, or other types of network servers.

Unlike rack or blade servers, tower servers are integrated desktop computers that take up a lot of space. As such, they are relatively more CPU capable, have fast read memory, are used to handle multi-user requests, and also provide different services such as DHCP or DNS.

Differences Among the Types of Servers

After the introduction of the above major three network server types, you have a preliminary understanding of the servers. Then, let's describe the difference between rack servers, blade servers, and tower servers.

Key Differences: Rack Server vs. Blade Server

In terms of form factor, the small size of a blade server makes it very limited in the components that provide computing performance, so you can fit more blades in the same space. Rack servers, on the other hand, are wide and short, which means you can only fit one server in a single section of the rack.

Compared with rack servers, blade servers are used more for high-performance processing of data clustering. The internal configuration is hot-swappable, which supports the removal or replacement of devices in the cluster for maintenance, reducing downtime. Rack servers equipped with corresponding cables and other facilities are relatively complete, all components operate independently, and additional memory, storage, and CPU are provided internally to support expansion.

They both have high humidity control and cooling costs. Rack server heat is determined by the number of servers placed inside, while blade server heat is determined by the number of initial installations. Generally speaking, blade servers are more concentrated than rack servers, so cooling costs are higher.

Key Differences: Rack Server vs. Tower Server

The difference between rack servers and tower servers is mainly reflected in size and management efficiency, and the computing performance is equivalent. Rack servers are much smaller than tower servers and can be placed in server cabinets for stack management, while tower servers are generally used in small offices or home networks and take up a lot of space.

Both servers are configured with independent components to provide scalability. The tower server requires less configuration and supports customization and upgrades for business needs, but the upgrade cost will be relatively high. In terms of heat dissipation, rack servers need to be equipped with appropriate cooling facilities, while tower servers only need peripherals such as monitors, and the cooling cost is lower.

Rack Server vs. Blade Server vs. Tower Server: How to Choose Them?

To increase data center storage and computing power, you must select at least one server type for your local architecture. As to rack servers, blade servers, and tower servers, here is a partial summary of the advantages. Rack servers have good computing performance, high scalability, and support stack management. Blade servers are suitable for data cluster processing and are equipped with hot-swappable to effectively reduce downtime. Tower servers are relatively large, with strong computing performance and low cooling consumption. As for heat dissipation, there are many server cooling technologies that can be used now.

Taking your business model into full consideration, if you are a medium-to-large enterprise with limited data center space but need multiple servers to handle high-end applications, you can choose blade servers to complete the deployment. But if your data center space is demanded by computing power, you can choose rack servers. For a small enterprise or home network, tower servers for storing files and deploying network resources would be better choices.

Conclusion

To sum up, rack servers, blade servers, and tower servers each have their advantages and features and can be applied to different scenarios. Many enterprises prefer rack servers because their computing power is comparable to tower servers. The volume is also relatively smaller than tower servers, while the cooling cost is lower than that of blade servers. What's more, the rack server also has its features and has good market prospects in the future.