ESXi Cluster with mixed CPU types?

[SteveR2345]

Hi, I understand adding new hosts with CPUs and newer features/higher clock speeds isn't ideal from a performance perspective.

Using EVC will allow this but at the lower EVC level. What about mixing hosts that have different socket and core counts in a cluster?

If I have a cluster with 4 socket 16core hosts (64 cores total), can I add in hosts with 2 sockets and 32 cores (64 cores) ? I'm assuming it would technically work might not be ideal as above?

What do we think? Any help appreciated please.

Thanks

Steve

[Akin Akalan]

It will work but no one can say it's ideal configuration. if the CPU family is different you must enable the EVC to the minimum family in the cluster. You can do some performance tests with evc enabled cluster and disabled.

You can check 2 link below.

https://www.vmware.com/content/dam/digitalmarketing/vmware/en/pdf/techpaper/performance/vsphere-esxi-vcenter-server-70-performance-best-practices.pdf

https://blogs.vmware.com/vsphere/2014/06/enhanced-vmotion-compatibility-evc-affect-performance.html

 

[dstadelmann]

Hi  

This will work. EVC is not looking for socket or core count. You will set the EVC level to the oldest CPU generation (like Skylake). Keep in mind, you cannot mix AMD and Intel CPU in the same cluster.

I recommend for performance perspective to work with VM affinity rules to make sure the VMs who require higher clock speed run on the hosts with the higher clock speed cpus and only in case of a failure on the lower clocked cpus.

Regards

Daniel