EFA that is Elastic Fabric Adapter, brings the scalability, elasticity and flexibility of the cloud to tightly-coupled applications. With the use of EFA, tightly-coupled applications get access to a lower and more consistent latency system and higher achieve throughput than traditional TCP channels, hence enabling them to scale in a better way. EFA support can also be enabled dynamically i.e. on-demand on any of the supported EC2 instance without any pre-reservation, hence giving you the flexibility to respond to changing business/workload priorities in a better way.