ECU – AWS’s measure of compute power relative to a reference processor.
ECU is Amazon’s measure of compute power, representing the relative measure of processing power of an AWS EC2 instance. One ECU provides the equivalent CPU capacity of a 1.0-1.2 GHz 2007 Opteron or 2007 Xeon processor. AWS uses ECUs to help customers compare compute capacity across different instance types and generations. Understanding ECUs helps in capacity planning and instance selection, particularly when dealing with CPU-intensive workloads. However, AWS has largely moved toward using vCPUs as the primary compute metric, with ECUs serving as a supplementary reference point.
