Exactly what hardware is dedicated to a single customer for an EC2 dedicated instance?

Question

The AWS documentation states that dedicated instances are run on hardware that’s dedicated to a single customer.

I can’t believe this means that a single dedicated instance will get a whole physical host to itself - surely that would be uneconomical for AWS, as dedicated instances only cost a small percentage more than regular instances.

So if my disbelief is true, it must mean that dedicated instances have some portion of a host dedicated to them. But what portion exactly? Do you get a physical CPU rather than a vCPU, and is that all? Does the rest of the physical host (motherboard, network interface, power supply, other bits) not count as hardware on which an instance is run?

Answer 1

From Dedicated Instances - Amazon Elastic Compute Cloud:

By default, EC2 instances run on shared tenancy hardware. Dedicated Instances are EC2 instances that run on hardware that's dedicated to a single customer. Dedicated Instances that belong to different AWS accounts are physically isolated at a hardware level, even if those accounts are linked to a single payer account. However, Dedicated Instances might share hardware with other instances from the same AWS account that are not Dedicated Instances.

That means the account gets the whole host computer. It is not shared with any other AWS account.