How can I get the number of CPU cores in Powershell?

user_1593077 0
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Suppose I'm running a (power)shell on a Windows machine.

Is there a one-liner I could use to get:

  1. The number of physical processor cores and/or
  2. The max number of in-flight threads, i.e. cores * hyper-threading factor?

Note: I want just a single number as the command output, not any headers or text.

windows-10 cpu powershell windows
3 Answers

Ran Turner's answer provides the crucial pointer, but can be improved in two ways:

  • The CIM cmdlets (e.g., Get-CimInstance) superseded the WMI cmdlets (e.g., Get-WmiObject) in PowerShell v3 (released in September 2012). Therefore, the WMI cmdlets should be avoided, not least because PowerShell (Core) (v6+), where all future effort will go, doesn't even have them anymore. Note that WMI still underlies the CIM cmdlets, however. For more information, see this answer.

  • Format-Table, as all Format-* cmdlets, is designed to produce for-display formatting, for the human observer, and not to output data suitable for later programmatic processing (see this answer for more information).

    • To instead create objects with a subset of the input objects' properties, use the Select-Object cmdlet. (If the output object(s) have 4 or fewer properties and aren't captured, they implicitly format as if Format-Table had been called; with 5 or more properties, it is implicit Format-List).

Therefore:

# Creates a [pscustomobject] instance with 
# .NumberOfCores and .NumberOfLogicalProcessors properties.
$cpuInfo =
  Get-CimInstance –ClassName Win32_Processor | 
     Select-Object -Property NumberOfCores, NumberOfLogicalProcessors

# Save the values of interest in distinct variables, using a multi-assignment.
# Of course, you can also use the property values directly.
$cpuPhysicalCount, $cpuLogicalCount = $cpuInfo.NumberOfCores, $cpuInfo.NumberOfLogicalProcessors

Of course, if you're only interested in the values (CPU counts as mere numbers), you don't need the intermediate object and can omit the Select-Object call above.

As for a one-liner:

If you want a one-liner that creates distinct variables, without repeating the - costly - Get-CimInstance call, you can use an aux. variable that takes advantage of PowerShell's ability to use assignments as expressions:

$cpuPhysicalCount, $cpuLogicalCount = ($cpuInfo = Get-CimInstance -ClassName Win32_Processor).NumberOfCores, $cpuInfo.NumberOfLogicalProcessors

  • To save the numbers in distinct variables and output them (return them as a 2-element array), enclose the entire statement in (...).

  • To only output the numbers, simply omit the $cpuPhysicalCount, $cpuLogicalCount = part.

user_453750

To find out processor number of cores using PowerShell

Get-WmiObject –class Win32_processor | ft NumberOfCores,NumberOfLogicalProcessors

To find out what is the number of threads running:

(Get-Process|Select-Object -ExpandProperty Threads).Count

user_74942180

There are several comments with similar answers. Get-WmiObject is deprecated. Go with Get-CimInstance. Do not use aliases in scripts. Spell commands and parameters out. Explicit is better than implicit.

Get-CimInstance –ClassName Win32_Processor | Format-Table -Property NumberOfCores,NumberOfLogicalProcessors

UPDATE:

If you want only a single number value assigned to a variable.

$NumberOfCores = (Get-CimInstance –ClassName Win32_Processor).NumberOfCores
$NumberOfLogicalProcessors = (Get-CimInstance –ClassName Win32_Processor).NumberOfLogicalProcessors
user_4479010
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