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High Performance Computing (HPC) is known as a domain where applications are well-optimized to get the highest performance possible on a platform. Unsurprisingly, a common question when moving a workload to AWS is what performance difference there may be from an existing on-premises bare metal platform. This blog will show the performance differential between bare metal instances and instances that use the AWS Nitro hypervisor is negligible for the evaluated HPC workloads.

TheAWS Nitro systemis a combination of purpose-built hardware and software designed to provide performance and security. Recent generation instances, including instance families popular with HPC workloads such as c5, c5n, m5zn, c6gn, andmany othersare based on the Nitro System. As shown in Figure 1, the AWS Nitro System is composed of three main components: Nitro cards, the Nitro security chip, and the Nitro hypervisor. Nitro cards provide controllers for the VPC data plane (network access), Amazon Elastic Block Store (Amazon EBS) access, instance storage (local NVMe), as well as overall coordination for the host. By offloading these capabilities to the Nitro cards, this removes the need to use host processor resources to implement these functions, as well as offering security benefits. The Nitro security chip provides a hardware root of trust and secure boot, among other features to help with system security.The Nitro hypervisor is lightweight hypervisor that manages memory and CPU allocation.

With this design, the host system no longer has direct access to AWS resources. Only the hardened Nitro cards can access other resources, and each of those cards provides software-defined hardware devices that are the only access points from the host device. With the I/O accesses handled by Nitro cards, this allows the last component, the Nitro hypervisor, to be light-weight and have a minimal impact to workloads running on the host. The Nitro hypervisor has only necessary functions, with a design goal of being quiescent, which means it should never activate unless it is doing work for an instance that requested it. This also means there are no background tasks running consuming any resources when it is not needed.

Figure 1. The AWS Nitro System building blocks.

The Nitro system architecture also allows AWS to offer instances that offer direct access to the bare metal of the host. Since their initial introduction in2017,many instance families offer *.metal variants, which provide direct access to the underlying hardware and no hypervisor. As in the case where the Nitro hypervisor is used, the Nitro cards are still the only access points to resources outside of the host. These instances are most commonly used for workloads that cannot run in a virtualized environment due to licensing requirements, or those that need specific hardware features only provided through direct access.

With both the option of bare metal instances and Nitro virtualized instances, this provides a method to show the performance differential between HPC application performance on bare metal vs running on the AWS Nitro hypervisor.

You can read the full blog to see how different HPC applications perform on Amazon EC2 instances with AWS Nitro hypervisor vs. bare metal instances.

Reminder: You can learn a lot from AWS HPC engineers by subscribing to the HPC Tech Short YouTube channel, and following the AWS HPC Blog channel.

Read more here:
Bare Metal Performance in the Cloud - HPCwire