Elastic Fabric Adapter (EFA) Cheat Sheet

• An Elastic Fabric Adapter (EFA) is a network device that you can attach to your Amazon EC2 instance to accelerate High Performance Computing (HPC) and machine learning applications.
• An EFA is an Elastic Network Adapter (ENA) with an additional OS-bypass functionality. 
• How It Works

• EFA integrates with 
  • Libfabric 1.9.0 and it supports Open MPI 4.0.2 and Intel MPI 2019 Update 6 for HPC applications, and 
  • Nvidia Collective Communications Library (NCCL) for machine learning applications.

• With an EFA, HPC applications use Intel Message Passing Interface (MPI) or Nvidia Collective Communications Library (NCCL) to interface with the Libfabric API. The Libfabric API bypasses the operating system kernel and communicates directly with the EFA device to place packets on the network.
• Supported operating systems
  • Amazon Linux 2
  • RHEL 7 and RHEL 8
  • CentOS 7
  • Rocky Linux 8 and 9
  • OpenSUSE Leap 15.4 and later
  • SUSE Linux Enterprise 15 SP2 and later
  • Ubuntu 18.04, 20.04, and 22.04

• Examples of HPC Applications
  • computational fluid dynamics (CFD)
  • crash simulations
  • weather simulations

Elastic Fabric Adapter Limitations

• • You can attach only one EFA per instance for instances that don’t support multiple network cards.
  • You can attach one EFA per network card for instances that support multiple network cards (e.g., c6in.32xlarge, dl1.24xlarge, hpc6id.32xlarge)
  • EFA OS-bypass traffic is limited to a single subnet. EFA traffic cannot be sent from one subnet to another. Normal IP traffic from the EFA can be sent from one subnet to another.
  • EFA is not supported on AWS Outposts.
  • EFA OS-bypass traffic is not routable. Normal IP traffic from the EFA remains routable.
  • The EFA must be a member of a security group that allows all inbound and outbound traffic to and from the security group itself.

Elastic Fabric Adapter (EFA) Pricing

EFA is available as an optional EC2 networking feature that you can enable on any supported EC2 instance at no additional cost.

Elastic Fabric Adapter Cheat Sheet References:

https://aws.amazon.com/hpc/efa/
https://aws.amazon.com/hpc/faqs/
https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/efa.html