A blade server, sometimes referred to as a high-density server, is a compact device containing a computer used to manage and distribute data in a collection of computers and systems, called a network. Its role is to act as a conduit between computers, programs, applications and systems.
A blade server typically consists of a chassis, or box-like structure, housing multiple thin, modular electronic circuit boards, known as server blades. They're called blades because of their ultra-thin shape. Each blade contains a single server, often dedicated to a single application. The information within blade servers is stored on a memory card or other memory device.
In addition, the individual blades contain processors, memory, integrated network controllers, an optional Fibre Channel (FC) host bus adapter and other input/output ports. These are used to connect server blades to other server blade units within the system or to connect individual blades to power sources.
A blade server is a small, modular server system made up of various parts that are all optimized to work together. The basic parts of a blade server system include the following:
To maximize their efficiency, blade servers are often dedicated to single-task functionality. Examples of tasks a server performs include the following:
Because most blade servers are dedicated and focused on a single-use application, they provide more control over how they're accessed and used as well as how data is transferred between devices.
The benefits of blade servers compared to their traditional predecessors include the following:
Blade servers are categorized by type based on various traits, such as differing CPUs, amount of RAM and cache memory or connections.
The following are key distinguishing characteristics in terms of the equipment used in blade servers:
Blade servers can be equipped with different CPUs such as Intel; AMD, or Advanced Micro Devices; Motorola; and Sun Microsystems. The CPU does the processing and computing for the entire system. The more powerful it is, the more functionality the computer system can provide at a given time.
A blade server can contain a variety of memory systems, including static RAM (SRAM), dynamic RAM (DRAM) and double data rate synchronous dynamic RAM (DDR SDRAM):
While blade servers have a modular, uniform design that makes them easy to move between data centers, they can have a variety of outer connectors. For example, they can be equipped with an Ethernet output, a token ring, a fiber channel that can be up to six miles long or a fieldbus network protocol. The bi-directional fieldbus network protocol enables communication between input and output devices without connecting each individual device back to the programmable logic controller. In addition, blade servers can be connected via different methods:
Blade servers, rack servers and tower servers are common features of data centers. While similar, they have some significant differences in terms of performance and form factor.
Blade servers, like rack-mounted servers, are typically stored in a vertical stack in a data center or server room. However, they often appear in larger data centers and are used for projects with higher power needs.
One key difference between blade servers and rack-mounted servers is that blade servers are stripped down, with simple, sometimes singular functionality. This allows for multiple small, flat, horizontal blades containing individual servers to be stored within a chassis and stacked vertically. Unlike rack servers, blade servers generally don't function as standalone servers. They work best when placed with other servers in a chassis and combined into a blade service stack.
Another major difference between rack servers and blade servers is that each individual blade server is typically dedicated to a single application, as it typically only contains a CPU, controller and memory. Blade server systems are easier to fix than larger rack-mounted servers because the modular parts can be repaired individually or hot-swapped without disrupting the larger system.
When an organization selects a specific model of blade server, it must consider the possibility of vendor lock-in. Switching between products is costly, as it involves a complete overhaul of all the available equipment. Blade servers also require fewer wires and cables than typical stack-mounted servers, and are powerful processors compared to the space they occupy.
Typically, rack servers -- also known as rack-mounted servers -- are created to fit vertically within a shelf-like structure, called a rack, that's housed in a data center or server room. They're ideal for projects with low CPU requirements or that require limited physical space.
The number of servers stacked within a rack-mounted system can vary depending on the size and extent of an organization's project needs. Rack servers are fully equipped to work as a standalone computer and can run multiple, complex applications and processes using powerful memory and CPU resources. Their modularity and configurability make them convenient to assemble and store. Without the need for a large chassis to hold the servers, rack-mounted servers are ideal for projects that require less than 10 servers.
Tower servers are integrated desktop PCs that are much larger than blade servers or rack servers. They have a more powerful CPU, fast read memory and offer additional services such as Dynamic Host Configuration Protocol or domain name system. Although rack servers are smaller and can fit in a server chassis, tower servers can be just as powerful in terms of computing power, enabling network administrators to stack more than one server in a closet. Additional processing power and storage can be added as needed.
While blade servers are common in many organizations' server rooms, other technologies are being used as well. Brick servers -- which, unlike a blade server, don't require a chassis outer container -- offer the benefits of compactness and adaptability. Similarly, cartridge servers are as small as printer cartridges and are commonly used in various industries. In addition, modular hybrid servers address some issues with hard-wired connections, temperature management and ease of movement within a server system.
As power consumption and thermal design power increase with ever-improving technologies, the demand for servers that can be stored seamlessly and easily cooled will continues to grow.
A server's strength and adaptability are huge advantages for businesses, but selecting the right server hardware can be challenging. Discover the best server for your needs by learning about the pros and cons of various server types.
29 Jun 2023