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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.

einpoklum
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  • @mklement0: I don't understand why you believe feedback should be provided so quickly. I don't work on this stuff every day. And even if I were to take a week or two... maybe I got sick? Maybe I was on vacation? Maybe I was busy with other things? The answer doesn't go stale (well, not for a good number of years anyway). – einpoklum Nov 09 '21 at 09:36
  • I _suspected_, based on the nature of your initial feedback and the fact that you've asked three more questions since, that you had abandoned this and your previous question, despite my asking for feedback repeatedly. I understand that it can take a while to give answers proper attention and that there should be no expectation of a specific time frame (and, of course, _no_ answer may deserve accepting). In the cases at hand, based on the discussion before activity ceased, it seemed trivial to bring closure, which is why I insisted. I am glad to see that my suspicion was incorrect. – mklement0 Nov 09 '21 at 12:54

3 Answers3

3

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  • The CIM cmdlets (e.g., Get-CimInstance) superseded the WMI cmdlets (e.g., Get-WmiObject) in PowerShell v3 (released in September 2012).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.

mklement0
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2

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

Ran Turner
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    As an aside: 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](https://stackoverflow.com/a/54508009/45375). – mklement0 Nov 06 '21 at 21:42
  • @mklement0: So, how do I get the number of physical/logical cores using Get-CimInstance, then? – einpoklum Nov 06 '21 at 21:51
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    Same class, and almost the exact same syntax. Run `Get-Help Get-CimInstance` to see the proper syntax, but it should be: `Get-CimInstance -ClassName win32_processor | Select NumberofCores` – Abraham Zinala Nov 06 '21 at 22:06
  • `Get-CimInstance –ClassName Win32_Processor | Format-Table -Property NumberOfCores,NumberOfLogicalProcessors` – lit Nov 07 '21 at 03:13
1

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
lit
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