WMI vs CIM speed tests–the final round

As a final test I want to see what happened when I ran multiple commands against the remote machine.

PS> 1..100 | foreach { Measure-Command -Expression{1..100 | foreach { Get-WmiObject -Class Win32_ComputerSystem -ComputerName W12SUS;
Get-WmiObject -Class Win32_OperatingSystem -ComputerName W12SUS;
Get-WmiObject -Class Win32_LogicalDisk -ComputerName W12SUS}} } |
Measure-Object -Average TotalMilliseconds

Count    : 100 Average  : 6986.797156 Sum      : Maximum  :
Minimum  : Property : TotalMilliseconds

PS> 1..100 | foreach { Measure-Command -Expression{1..100 | foreach { Get-CimInstance -ClassName Win32_ComputerSystem -ComputerName W12SUS; Get-CimInstance -ClassName Win32_OperatingSystem -ComputerName W12SUS; Get-CimInstance -ClassName Win32_LogicalDisk -ComputerName W12SUS}} } | Measure-Object -Average TotalMilliseconds

Count    : 100 Average  : 8430.833188 Sum      : Maximum  :
Minimum  : Property : TotalMilliseconds

PS> $sess = New-CimSession -ComputerName W12SUS PS> 1..100 | foreach { Measure-Command -Expression{1..100 | foreach {
Get-CimInstance -ClassName Win32_ComputerSystem -CimSession $sess;
Get-CimInstance -ClassName Win32_OperatingSystem -CimSession $sess;
Get-CimInstance -ClassName Win32_LogicalDisk -CimSession $sess}} } |
Measure-Object -Average TotalMilliseconds

Count    : 100 Average  : 3460.203938 Sum      : Maximum  :
Minimum  : Property : TotalMilliseconds

WMI is slightly faster than CIM but using a CIM session is by far and away the fastest.

My conclusion is that WMI and CIM are comparable, with WMI having a slight edge for speed. If you want to run multiple commands against a remote machine you need to use a CIM session as it is way faster.