Listing processes by CPU usage percentage in powershell

There are several points to note here:

• first, you have to use the $_ variable to refer to the object currently coming from the pipe.

• second, Powershell does not use % to express percentage -- instead, % represents the modulus operator. So, when ou want percentage, you have to transform your number by yourself by simply multiplying it by 0.01.

• third, the Get-Process cmdlet does not have a field CPU_Usage; a summary on its output can be found here. About the field CPU is says: "The amount of processor time that the process has used on all processors, in seconds." So be clear on what you can expect from the numbers.

Summarizing the command can be written as

Get-Process | Where-Object { $_.CPU -gt 100 }

This gives you the processes which have used more than 100 seconds of CPU time.

If you want something like a relative statement, you first have to sum up all used times, and later divide the actual times by the total time. You can get the total CPU time e.g. by

Get-Process | Select-Object -expand CPU | Measure-Object -Sum | Select-Object -expand Sum

Try to stack it together with the previous command.

Further improving earlier answers by adding dynamic detection of the number of logic cores so the percentage can be adjusted back to what us common mortals expect to see, where 100% means all of the CPU bandwidth of the machine, and there is no value greater than 100%. Includes a filter set at 10%, which one can adjust as appropriate. The assumption is that people will be interested in finding processes with high overload processor usage and not want to list the numerous idle processes of the machine.

$NumberOfLogicalProcessors=(Get-WmiObject -class Win32_processor | Measure-Object -Sum NumberOfLogicalProcessors).Sum
(Get-Counter '\Process(*)\% Processor Time').Countersamples | Where cookedvalue -gt ($NumberOfLogicalProcessors*10) | Sort cookedvalue -Desc | ft -a instancename, @{Name='CPU %';Expr={[Math]::Round($_.CookedValue / $NumberOfLogicalProcessors)}}

Sample output:

InstanceName CPU %
------------ -----
_total         100
idle           100

If you want CPU percentage, you can use Get-Counter to get the performance counter and Get-Counter can be run for all processes. So, to list processes that use greater than say 5% of CPU use:

(Get-Counter '\Process(*)\% Processor Time').CounterSamples | Where-Object {$_.CookedValue -gt 5}

This will list the processes that was using >5% of CPU at the instance the sample was taken. Hope this helps!

I was looking for a solution to get cpu, mem utilization by process. All solutions I tried where I would get the cpu but those numbers were not matching with taskmanager. So I wrote my own. Following will provide accurate cpu utilization by each process. I tested this on a I7 laptop.

$Cores = (Get-WmiObject -class win32_processor -Property numberOfCores).numberOfCores;
$LogicalProcessors = (Get-WmiObject –class Win32_processor -Property NumberOfLogicalProcessors).NumberOfLogicalProcessors;
$TotalMemory = (get-ciminstance -class "cim_physicalmemory" | % {$_.Capacity})

 

$DATA=get-process -IncludeUserName | select @{Name="Time"; Expression={(get-date(get-date).ToUniversalTime() -uformat "%s")}},`
  ID,  StartTime,  Handles,WorkingSet, PeakPagedMemorySize,  PrivateMemorySize, VirtualMemorySize,`
   @{Name="Total_RAM"; Expression={ ($TotalMemory )}},`
  CPU,
   @{Name='CPU_Usage'; Expression = { $TotalSec = (New-TimeSpan -Start $_.StartTime).TotalSeconds
     [Math]::Round( ($_.CPU * 100 / $TotalSec) /$LogicalProcessors, 2) }},`
   @{Name="Cores"; Expression={ ($Cores )}},`
   @{Name="Logical_Cores"; Expression={ ($LogicalProcessors )}},`
 
 UserName, ProcessName, Path |  ConvertTo-Csv 

Or as [pscustomobject]:

$cpu   = Get-WmiObject –class Win32_processor -Property NumberOfCores, NumberOfLogicalProcessors
$mem   = (Get-CimInstance -class cim_physicalmemory | measure capacity -sum).sum
$epoch = get-date(get-date).ToUniversalTime() -uformat "%s"

get-process -IncludeUserName | 
% { 
  if ($_.starttime -gt 0) {
    $ts       = (New-TimeSpan -Start $_.StartTime -ea si).TotalSeconds
    $cpuusage = [Math]::Round( $_.CPU * 100 / $ts / $cpu.numberoflogicalprocessors, 2)
  } else {
    $cpuusage = 0
  }

  [pscustomobject] @{
    "Time"                = $epoch
    "Total_RAM"           = $mem
    "CPU_Usage"           = $cpuusage
    "Cores"               = $cpu.numberofcores
    "Logical Cores"       = $cpu.numberoflogicalprocessors
    "UserName"            = $_.username
    "ProcessName"         = $_.processname
    "Path"                = $_.path
    "CPU"                 = $_.CPU
    "ID"                  = $_.ID
    "StartTime"           = $_.StartTime
    "Handles"             = $_.Handles
    "WorkingSet"          = $_.WorkingSet
    "PeakPagedMemorySize" = $_.PeakPagedMemorySize
    "PrivateMemorySize"   = $_.PrivateMemorySize
    "VirtualMemorySize"   = $_.VirtualMemorySize
  }
}