Enhanced vMotion Capability (EVC)

Enhanced vMotion Capability (EVC) is a cluster feature that enables vMotion between different processor (CPU) generations of the Intel Flex Migration or AMD-V Extended Migration technologies (Intel and AMD processors still cannot be mixed in a cluster!). vMotion requires that each processor of the ESXi hosts in a cluster can provide the same functionality. This is achieved by EVC by masking the new features of newer processors for a virtual machine. By masking these new features the same processor functional level is created across the entire cluster.
With EVC is it possible to combine different processor generations in a cluster and still make sure that virtual machines can be moved from one ESXi host to another using vMotion. EVC masks the new processor functionality for the virtual machines in the cluster. However the new processor features are not disabled.
It is understandable that EVC has impact on only the new processor features such as AMD and SSE instructions. EVC has no effect on processor speed and processor cache levels. Hardware virtualization technologies such as Intel and AMD RVI EPT will still be available for the VMkernel if EVC is enabled.