When you think about infrastructure as a service, you typically pay for a virtual machine that resides in a multi-tenant environment. That means, it's using a set of shared resources. For many companies that approach is fine, but when a customer wants more control, they may prefer a single tenant system where they control the entire set of hardware resources. This approach is also known as "bare metal" in the industry, and today AWS announced five new bare metal instances.
You end up paying more for this kind of service because you are getting more control over the processor, storage and other resources on your own dedicated underlying server. This is part of the range of products that all cloud vendors offer. You can have a vanilla virtual machine, with very little control over the hardware, or go with bare metal and get much finer grain control over the underlying hardware, something that companies require if they are going to move certain workloads to the cloud.
As AWS, it describes in the blog post announcing these new instances, these are for highly specific use cases. “Bare metal instances allow EC2 customers to run applications that benefit from deep performance analysis tools, specialized workloads that require direct access to bare metal infrastructure, legacy workloads not supported in virtual environments, and licensed-restricted Tier 1
The five new products, called m5.metal, m5d.metal, r5.metal, r5d.metal, and z1d.metal (catchy names there, Amazon) offer a variety of resources:
These new offerings are available today as on-demand, reserved or spot instances, depending on your requirements.