How do I find the CPU and RAM usage using PowerShell?

I am trying to get PowerShell to give me the RAM and CPU usage, but I can't figure out what WMI class to use. My computer has two processors, so it would be useful to have the information for both of them.

You can also use the Get-Counter cmdlet (PowerShell 2.0):

Get-Counter '\Memory\Available MBytes'
Get-Counter '\Processor(_Total)\% Processor Time'

To get a list of memory counters:

Get-Counter -ListSet *memory* | Select-Object -ExpandProperty  Counter

Get-WmiObject Win32_Processor | Select LoadPercentage | Format-List

This gives you CPU load.

Get-WmiObject Win32_Processor | Measure-Object -Property LoadPercentage -Average | Select Average

I use the following PowerShell snippet to get CPU usage for local or remote systems:

Get-Counter -ComputerName localhost '\Process(*)\% Processor Time' | Select-Object -ExpandProperty countersamples | Select-Object -Property instancename, cookedvalue| Sort-Object -Property cookedvalue -Descending| Select-Object -First 20| ft InstanceName,@{L='CPU';E={($_.Cookedvalue/100).toString('P')}} -AutoSize

Same script but formatted with line continuation:

Get-Counter -ComputerName localhost '\Process(*)\% Processor Time' `
    | Select-Object -ExpandProperty countersamples `
    | Select-Object -Property instancename, cookedvalue `
    | Sort-Object -Property cookedvalue -Descending | Select-Object -First 20 `
    | ft InstanceName,@{L='CPU';E={($_.Cookedvalue/100).toString('P')}} -AutoSize

On a 4 core system it will return results that look like this:

InstanceName          CPU
------------          ---
_total                399.61 %
idle                  314.75 %
system                26.23 %
services              24.69 %
setpoint              15.43 %
dwm                   3.09 %
policy.client.invoker 3.09 %
imobilityservice      1.54 %
mcshield              1.54 %
hipsvc                1.54 %
svchost               1.54 %
stacsv64              1.54 %
wmiprvse              1.54 %
chrome                1.54 %
dbgsvc                1.54 %
sqlservr              0.00 %
wlidsvc               0.00 %
iastordatamgrsvc      0.00 %
intelmefwservice      0.00 %
lms                   0.00 %

The ComputerName argument will accept a list of servers, so with a bit of extra formatting you can generate a list of top processes on each server. Something like:

$psstats = Get-Counter -ComputerName utdev1,utdev2,utdev3 '\Process(*)\% Processor Time' -ErrorAction SilentlyContinue | Select-Object -ExpandProperty countersamples | %{New-Object PSObject -Property @{ComputerName=$_.Path.Split('\')[2];Process=$_.instancename;CPUPct=("{0,4:N0}%" -f $_.Cookedvalue);CookedValue=$_.CookedValue}} | ?{$_.CookedValue -gt 0}| Sort-Object @{E='ComputerName'; A=$true },@{E='CookedValue'; D=$true },@{E='Process'; A=$true }
$psstats | ft @{E={"{0,25}" -f $_.Process};L="ProcessName"},CPUPct -AutoSize -GroupBy ComputerName -HideTableHeaders

Which would result in a $psstats variable with the raw data and the following display:

   ComputerName: utdev1

           _total  397%
             idle  358%
             3mws   28%
           webcrs   10%


   ComputerName: utdev2

           _total  400%
             idle  248%
             cpfs   42%
             cpfs   36%
             cpfs   34%
          svchost   21%
         services   19%


   ComputerName: utdev3

           _total  200%
             idle  200%

I have combined all the above answers into a script that polls the counters and writes the measurements in the terminal:

$totalRam = (Get-CimInstance Win32_PhysicalMemory | Measure-Object -Property capacity -Sum).Sum
while($true) {
    $date = Get-Date -Format "yyyy-MM-dd HH:mm:ss"
    $cpuTime = (Get-Counter '\Processor(_Total)\% Processor Time').CounterSamples.CookedValue
    $availMem = (Get-Counter '\Memory\Available MBytes').CounterSamples.CookedValue
    $date + ' > CPU: ' + $cpuTime.ToString("#,0.000") + '%, Avail. Mem.: ' + $availMem.ToString("N0") + 'MB (' + (104857600 * $availMem / $totalRam).ToString("#,0.0") + '%)'
    Start-Sleep -s 2
}

This produces the following output:

2020-02-01 10:56:55 > CPU: 0.797%, Avail. Mem.: 2,118MB (51.7%)
2020-02-01 10:56:59 > CPU: 0.447%, Avail. Mem.: 2,118MB (51.7%)
2020-02-01 10:57:03 > CPU: 0.089%, Avail. Mem.: 2,118MB (51.7%)
2020-02-01 10:57:07 > CPU: 0.000%, Avail. Mem.: 2,118MB (51.7%)

You can hit Ctrl+C to abort the loop.

So, you can connect to any Windows machine with this command:

Enter-PSSession -ComputerName MyServerName -Credential MyUserName

...paste it in, and run it, to get a "live" measurement. If connecting to the machine doesn't work directly, take a look here.

To export the output to file on a continuous basis (here every five seconds) and save to a CSV file with the Unix date as the filename:

while ($true) {
     [int]$date = get-date -Uformat %s
     $exportlocation = New-Item -type file -path "c:\$date.csv"
     Get-Counter -Counter "\Processor(_Total)\% Processor Time" | % {$_} | Out-File $exportlocation
     start-sleep -s 5
}