An engineer researching why modern Nitro-based EC2 instance types deliver almost all of a host's CPU and memory resources to customer workloads, while still providing high-speed networking and low-latency EBS access, asks what makes this possible. What is the correct explanation?
- AWS removed the hypervisor entirely, so instances run directly on bare hardware with no virtualization layer at all
- A software-only hypervisor upgrade eliminated the need for any dedicated hardware changes
- Every Nitro-based instance type is automatically billed as a Dedicated Host at no extra charge
- Dedicated Nitro Cards offload networking, storage, and security functions from the host CPU, while a lightweight Nitro Hypervisor and a Nitro Security Chip handle the rest
Why D? And why not the others?
Correct answer: D. Dedicated Nitro Cards offload networking, storage, and security functions from the host CPU, while a lightweight Nitro Hypervisor and a Nitro Security Chip handle the rest
The Nitro System splits traditional hypervisor responsibilities across dedicated hardware components: Nitro Cards handle networking, EBS storage I/O, and security functions outside the main host CPU, the Nitro Hypervisor itself is reduced to a thin layer mainly responsible for CPU and memory allocation, and the Nitro Security Chip acts as a hardware root of trust that continuously monitors and protects the system's hardware and firmware. This offloading is precisely why Nitro-based instances can deliver nearly all of a host's compute and memory to the customer's workload while still providing high-throughput networking and low-latency EBS performance. Claiming the hypervisor was removed entirely is inaccurate — the Nitro Hypervisor still exists, just minimized rather than eliminated. The improvement is also not a mere software upgrade; it required purpose-built Nitro Card hardware alongside the software changes. Nitro-based instance types remain ordinary shared or dedicated-tenancy instances depending on what a customer selects at launch; using the Nitro System has no automatic effect on tenancy or Dedicated Host billing.
Source: AWS documentation: AWS Nitro System overview (aws.amazon.com/ec2/nitro)