Enhanced vMotion Compatibility (EVC) is a technique that allows vMotion to proceed even when ESXi hosts with CPUs of different technologies exist in the vMotion destination cluster. EVC assigns a baseline to all ESXi hosts in the destination cluster so that all of them will be compatible for vMotion. An example is assigning a Nehalem baseline to a cluster mixed with ESXi hosts with Westmere, Nehalem processors. In this case, the features available in Westmere would be hidden, because it is a newer processor than Nehalem. But all ESXi hosts would “broadcast” that they have Nehalem features.

Tests showed how utilizing EVC with different applications affected their performance. Several workloads were chosen to represent typical applications running in enterprise datacenters. The applications represented included database, Java, encryption, and multimedia. To see the results and learn some best practices for performance with EVC, read Impact of Enhanced vMotion Compatibility on Application Performance.