Determining a target vCPU to Core Ratio

[TheVMinator]

Each socket in my physical servers has 4 cores per socket.  How should I determine the optimal target vCPU to physical core ratio?  I want to make sure the vCPUs on my VMs are not waiting to be scheduled on physical cores.  At the same time I don't want to needlessly limit my consolidation ratio for fear of having too many vCPUs per core.  In this case I have enough processing capacity in terms of GHz on my cluster.

[abhilashhb]

We usually size with 2vCPU's per core to 4vCPU's per core for a production VM depending on the resources it requires. If its test and dev we take 8vCPU's per core. It depends on the Apps that you put on the VM's too. If they are processor intensive then you need to be easy with the ratio.

[TheVMinator]

OK thanks for the input.  Anyone else with best practices, research or links on good targets for CPU to core ratios?