Here’s a quick and dirty one-liner to find the total allocated CPU & Memory per ESXi host basis. This is useful when you want to get a quickly get your over-commitment ratios.
$TotalMem=0; Get-VMHost myESXiHost1 | Get-VM | ?{$_.PowerState -match 'PoweredOn'} | %{$TotalMem=$TotalMem+$_.MemoryGB};Write-Host $TotalMem $TotalCPU=0; Get-VMHost myESXiHost2 | Get-VM | ?{$_.PowerState -match 'PoweredOn'} | %{$TotalCPU = $TotalCPU+$_.numCPU};Write-Host $TotalCPU