What is a bare metal server?

Unlike traditional cloud computing, which is based on virtual machines, bare metal servers do not come with a hypervisor preinstalled and give the user complete control over their server infrastructure.

With a bare metal server, because users get complete control over the physical machine, they have the flexibility to choose their operating system, avoid the noisy neighbor challenges of shared infrastructure, and finely tune hardware and software for specific, often data-intensive, workloads.

Along with virtual machines, networking and storage, bare metal servers are a foundational component of the infrastructure-as-a-service (IaaS) stack in cloud computing.

The primary benefits of bare metal servers are based on the access to users' hardware resources. The advantages of this approach include the following:

• Enhanced physical isolation and the associated security and regulatory benefits.
  
  
• Greater processing power.
  
  
• Complete control of their software stack.
  
  
• More consistent disk and network input or output (I/O) performance.
  
  
• Greater quality of service by eliminating the noisy neighbor phenomenon.

Bare metal servers have an important role in the infrastructure mix for many companies due to their unique combination of performance and control.

The terms bare metal server and dedicated server are sometimes used interchangeably, and bare metal servers are dedicated services. But while they are similar, they are not synonymous. The difference is less about the servers themselves, and more about how they are delivered by the service provider.

Historically, dedicated servers have been associated with long provisioning times, billing increments of months or years, and often low-end or even dated hardware.

The concept of bare metal servers rose as a response to the sometimes negative associations with dedicated servers and hosting. Providers specializing in bare metal servers offer dedicated hardware in something much closer to a cloud service model, with provisioning times in minutes, by the hours, and hardware ranging from inexpensive to top-of-the-line components, including graphic processing units. Dedicated servers remain as a lower-priced alternative for users who don’t require these attributes.

Today, available computing options for cloud services go beyond bare metal and cloud servers. Containers are becoming a default infrastructure choice for many cloud-native applications. Platform-as-a-service (PaaS) has an important niche in the applications market for developers who don’t want to manage an operating system or runtime environment. And serverless computing is emerging as the model of choice for cloud purists.

But the comparison most users still gravitate toward when evaluating dedicated or bare metal servers is the comparison to virtual servers, and for most companies, the criteria for choice are application- or workload-specific. It is common for a company to use a mix of dedicated or bare metal and virtualized resources across their cloud environment.

Virtual servers are the more common model of cloud computing because they offer greater resource density, faster provisioning times and the ability to scale up and down quickly as needs dictate. But dedicated or bare metal servers are the right fit for a few primary use cases that take advantage of the combination of attributes centered on dedicated resources, greater processing power and more consistent disk and network I/O performance:

• Performance-centric app and data workloads: The complete access and control over hardware resources make bare metal a good match for workloads, such as high-performance computing, big data, high-performance databases, gaming and finance workloads.
  
  
• Apps with complex security or regulatory requirements: The combination of a global data center footprint with physical resource separation has helped many organizations adopt the cloud while simultaneously meeting complex security and regulatory demands.
  
  
• Large, steady-state workloads: For applications such as enterprise resource planning, customer relationship management or supply chain management that have a relatively stable set of ongoing resource demands, bare metal can also be a good fit.