EVC Mode disabled

[vmproteau]

I recently joined a company and found that they have disabled EVC mode on all their clusters. I always enable it so hadn't reviewed the implications recently.

1. I assume with all Host identical, EVC being disabled would be the equivilant of enabling it at the proper EVC mode...correct?
2. Besides the obvious reason to enable it (to ensure compatibility when you do eventually add a Host with a newer processor), are there any other benefits to EVC (or drawbacks to disabling) that I'm not thinking of?

[weinstein5]

1) With all host being identical there will be no masking of CPU feature sets

2) You are no drawbacks not to have it enabled if all the hosts are the same -

[vmproteau]

Thanks. What about a scenario where you have EVC mode disabled. All your Hosts are "Sandy Bridge" so there is no detrimental effect. Down the road you get an "Ivy Bridge" Host. For this Host to participate in the cluster, you would now need to enable EVC Mode for "Sandy Bridge".

If I recall, you can dynamically modify EVC modes without affecting VMs (they just won't notice the change until VM power cycle. Does that also apply to "enabling" EVC mode on the fly? Could I enable EVC mode, set it to "Sandy Bridge", add the "Ivy Bridge Host to the cluster and start moving VMs to it?