we have a Cluster with 5 ESXi's
|Available CPU||# core||Logical proccessor|
and other 2 ESXi's are same as last
most vms use 2 vCPUs and few have 2*2 vCPUs but in general CPU usage isnt high for the different VMs
so from CPU Point of View
how to know when to stop having more vms on the ESXi's in general ?
keep a look at the cpu ready value of your vCPU's. Once it reaches a threshold of 10% (2000ms in vCenter performance chart - real-time) your vCPU to pCPU consolidation rate is far too high.
Of course it all depends on your requirements in your applications / SLAs.
ready is a good indicator, since it reflects the "processing-latency" of your virtual machine. There are a lot of articles explaining this