Rack Servers

What are rack servers?

Rack servers are computer servers designed to be mounted within a server rack. Rack servers are typically used in data centers and other enterprise-level computing environments, and they are designed to be highly scalable, reliable, and efficient.

Rack servers are designed for density with many fitting within a  single rack, allowing for efficient use of space in data centers. Rack servers come in different form factors known as “U” standard which is equal to 44.45mm (1.75”) of rack height. The depth of the rack and servers can vary depending on the equipment required but rages from 600 – 1200mm. The most common is 1U and 2U whereby the larger servers can support more memory, storage, graphics or networking cards. They typically have higher performance processors, memory, storage and networking capabilities, making them ideal for running large-scale applications and databases. These servers are designed to offer high performance, reliability, scalability and run a wide range of workloads – virtualized, containerized and bare metal. 

How do organizations choose rack servers?

Organizations select rack servers depending on a variety of considerations, such as their computing requirements, finances, and projected future development. When selecting rack servers, enterprises should keep the following important criteria in mind:

  • Processing Power: The server's processing power is one of the main factors that businesses take into account. The server must be able to manage the burden of the organization without sluggishness or causing downtime. When selecting a rack server, organizations may need to take into account elements like the number of cores, clock speed, and cache capacity.
  • Memory and Storage: Organizations must ensure that the rack server has sufficient memory and storage to meet their computing requirements. This might entail taking into account variables like RAM size, storage type (SSD or HDD), and storage capacity.
  • Scalability: When selecting a rack server, organizations must take their long-term expansion ambitions into account. They want a server that can expand to accommodate growing demand without necessitating an extensive redesign of the IT infrastructure.
  • Power and cooling: Due to the density and scalability, rack servers consume a lot of power and produce a lot of heat. The server room or data center of an organization must have sufficient power and cooling equipment to sustain its rack servers.
  • Manageability and Support: Businesses require servers that are simple to run and support. They must make sure they have the assistance and tools needed to handle and resolve any potential problems. 
  • Budget: Rack servers come in different sizes and are optimized for different workloads so it important for an organization to understand the both short long term needs to ensure the balance cost, performance and reliability.

How do rack servers work?

Rack servers are designed to be mounted vertically in a standard server rack, which is a specialized cabinet or frame that provides a standardized way to store and organize multiple servers in a data center or server room. Here is a general overview of how rack servers work:

  • Power and Networking: Rack servers are typically powered by a redundant power supply to ensure that they remain operational even if one power supply fails. They are also connected to the network typically using redundant high-speed Ethernet cables to allow for communication between servers and users.
  • Operating System and Applications: Rack servers support wide range of operating systems (such as Windows or Linux) or hypervisors (OS virtualization) ,  . They are designed for large compute workloads or for sharing resources and services like email, collaboration and web . Once the server is powered on, the operating system and applications are loaded into memory, allowing users to interact with the server via a remote console or other interface.
  • Data Storage: Rack servers typically have multiple hard drives or solid-state drives (SSDs) for data storage. The data can be stored locally on the server or on a centralized storage system such as a storage area network (SAN) or network-attached storage (NAS).
  • Processing Power: Rack servers have powerful processors (CPUs) with multiple cores to handle complex computing tasks. They also have large amounts of memory (RAM) to support the processing of large data sets and applications.
  • Virtualization: Rack servers can be used for virtualization, which allows multiple operating systems and applications to run on a single physical server. This can help organizations save on hardware costs and improve the efficiency of their computing infrastructure.

What is the difference between tower, rack, and blade servers?

Here are the following featured differences between tower, rack and blade servers:


  • Form Factor
  • Space Requirements
  • Scalability
  • Computing Power
  • Flexibility
  • Power and Cooling

Tower Server

  • Vertical tower case that can sit on a desk or floor.
  • Require some floor space and cannot be racked. 
  • Limited scalability due to physical size and lack of rack.
  • Typically have lower computing power and storage capacity compared to rack and blade servers.
  • Limited flexibility due to the fixed form factor.
  • Generally consume less power and generate less heat than rack and blade servers.

Rack Server

  • Rectangular enclosure that can be mounted vertically in a server rack.
  • Require less floor space and can be easily stacked in server racks.
  • With often up to 42 servers per rack these can be scaled easily.
  • Can offer high computing power and storage capacity with support for multiple processors, more memory, and more storage.
  • Offer more flexibility with the ability to add or remove servers based on changing needs.
  • Require more power and cooling due to higher computing power and density.

Blade  Server

  • Modular server that can be installed in a specialized chassis that sits in a rack.
  • Require the least amount of floor space and can be densely packed in a blade chassis.
  • Highly scalable due to the ability to add more server modules to the blade chassis.
  • Offer high computing power and storage capacity with support for multiple processors, high-speed networking, and shared storage.
  • Offer the most flexibility with the ability to mix and match server modules and easily replace or upgrade individual components.
  • Require significant power and cooling infrastructure to support the high density and performance.

HPE and Rack Servers

Here are related HPE rack server products and services:

  • HPE ProLiant Servers: A family of industry-leading servers that deliver performance, reliability, and security for a wide range of workloads.
  • HPE ProLiant Solutions: A set of workload-optimized solutions that leverage the power of HPE ProLiant servers to deliver specific business outcomes, such as virtualization, database management, and high-performance computing.
  • HPE GreenLake for Compute Ops Management: A cloud-based suite of tools and services that help businesses automate the lifecycle and updates of their compute infrastructure wherever it is located.
  • HPE Integrated Lights-Out (iLO): Gain consistent insight into the health and operation of your HPE ProLiant servers.  Automate and simplify server management.  Security initiated in the supply chain and rooted in the silicon.
  • HPE Rack Servers: A range of rack-mounted servers designed for medium to large businesses that require high computing power, scalability, and reliability.
  • HPE OneView:   HPE OneView is an integrated infrastructure management software that offers effective control of computing, storage, and networking resources as well as facilitates provisioning, monitoring, and upgrading across HPE hardware infrastructure.
  • HPE Simplivity:   HPE SimpliVity is a hyperconverged infrastructure solution that integrates storage, compute, and networking in a single, easy-to-manage platform that provides high performance, scalability, and efficiency for virtualized workloads, as well as built-in data protection and disaster recovery features.
  • HPE Synergy:  HPE Synergy is a powerful composable infrastructure solution that helps enterprises to expedite application delivery and development, optimize IT operations, and cut costs by dynamically assembling resources to meet workload requirements. It makes it possible for computing, storage, and networking resources to be quickly provisioned, providing the flexibility and agility needed to adapt to changing business demands.
  • HPE Compute Security: A comprehensive set of security solutions designed to protect HPE ProLiant servers and other IT assets against cyber threats.

Server Virtualization: A technology that allows multiple virtual servers to run on a single physical server, maximizing hardware utilization and reducing costs.

Tower Servers: Standalone servers that are suitable for small businesses or individual users.

Virtual Server: A software-based server that runs on a physical server and behaves like a physical server, but with the ability to run multiple virtual servers simultaneously.