This script outputs the pCPU/ vCPU ratio for each ESXi host.

Get-CpuRatio

#requires -Version 1
#requires -PSSnapin VMware.VimAutomation.Core

function Get-CpuRatio  {

    <#
            .SYNOPSIS
            No parameters needed. Just execute the script.

            .DESCRIPTION
            This script outputs the pCPU/ vCPU ratio for each ESXi host. Only the number of
            physical cores is taken into account, not the number of logical processors 
            (physical cores + hyperthreading)
     
            .EXAMPLE
            Get-CpuRatio

            Get the pCPU/ vCPU ratio for all ESXi hosts.
    
            .NOTES
            Author: Patrick Terlisten, patrick@blazilla.de, Twitter @PTerlisten
    
            This script is provided "AS IS" with no warranty expressed or implied. Run at your own risk.

            This work is licensed under a Creative Commons Attribution NonCommercial ShareAlike 4.0
            International License (https://creativecommons.org/licenses/by-nc-sa/4.0/).
    
            .LINK
            http://www.vcloudnine.de
    #>

    # Create empty hash table
    $OutputTable = @()

    # Get a list of all ESXi Hosts 
    $VMHosts = Get-VMHost

    # Get a list of all VMs
    $VMs = Get-VM

    try

    {
        # Loop through the ESXi hosts 
        ForEach ($VMHost in $VMHosts) {
            # Init variable
            $vCPUs = 0
            $Ratio = 0
    
            # Get the number of physical cores of the current ESXi host
            $Cores = $VMHost.extensiondata.hardware.cpuinfo.NumCpuCores
    
            # Summarize the number of vCPUs for all VMs on the current host
            $VMs  | Where-Object -FilterScript {$_.vmhost -like $VMHost} | ForEach-Object -Process {$vCPUs += $_.numcpu}
        
            # If vCPU count is > 0, calculate the ratio of vCPUs to pCPUs
            if ($vCPUs -ne '0') {$Ratio = "$('{0:N2}' -f ($vCPUs / $Cores))" + ':1'}
 
            # Build Output
            $Output = '' | Select-Object -Property Hostname, Cores, vCPUs, Ratio
            $Output.Hostname += $VMHost.name
            $Output.Cores += $Cores
            $Output.vCPUs += $vCPUs
            $Output.Ratio += $Ratio
    
            # Fill $OutputTable
            $OutputTable += $Output
        }
    }
    
    catch
    
    {
        "Error was $_"
        $line = $_.InvocationInfo.ScriptLineNumber
        "Error was in Line $line"
    }

    finally
    
    {
        # Write OutputTable and sort by ratio
        $OutputTable | Sort-Object -Property @{Expression = 'Ratio';Descending = $true} | Format-Table -AutoSize
    }
}