EVC understanding, is this right?

Hi All,

Just wanted to check I understand this correctly, forgive me if this should have be asked in a different section?

I have a vSphere 5.1 HA Cluster with hosts running Intel Xeon X5670 and E5620.  Wiki says these are in the same family Westmere: http://en.wikipedia.org/wiki/Xeon  I have EVC disabled.

Am I right in thinking I could enable EVC mode to the Westmere Generation and lose nothing from the CPU Instruction sets used and this would then enforce any new hosts added to the cluster to comply with the baseline?

Many thanks