How to Measure Runtime of a Script Using PowerShell

It is expected to check for the runtime of a script after creating it. It helps the developer gauge the script with measurable values if any revisions that will make the script slower or faster.

In Windows PowerShell, there is a way to measure this, and in this article, we will learn how to do that exactly.

Use Measure-Command Cmdlet to Measure Runtime of a Script in PowerShell

Using the Measure-Command cmdlet in PowerShell is easy to measure the runtime or execution time. This command can also tell you how long a custom function or an entire script takes to execute.

The Measure-Command is a cmdlet that is easy to use and provides intuitive, actionable output.

The Measure-Command cmdlet requires two parameters: -Expression and -InputObject. The -InputObject parameter represents one or more expressions in any way.

It’s simple but provides valuable metrics to give you a glimpse into the performance of your code.

Let’s use Measure-Command in a performance-tuning example. Say we have an array defined as $arr01 = @().

We’ll use integers created with a range to keep it simple. We’ll add these numbers to the array using +=.

$arr01 = @()
0..10000 | ForEach-Object { $arr01 += $_ }

The snippet above executes, but for how long? Let’s find out with Measure-Command.

First, we can wrap the code inside a script block representing an expression and use that as the Expression parameter for Measure-Command.

Example Code:

Measure-Command -Expression { 0..10000 | ForEach-Object { $arr01 += $_ } }

Output:

Days              : 0
Hours             : 0
Minutes           : 0
Seconds           : 0
Milliseconds      : 76
Ticks             : 762558
TotalDays         : 8.82590277777778E-07
TotalHours        : 2.11821666666667E-05
TotalMinutes      : 0.00127093
TotalSeconds      : 0.0762558
TotalMilliseconds : 76.2558

Notice that Measure-Command returns time broken down into various categories. We don’t need to perform any mathematical operations to convert seconds, minutes, or hours.

It’s all part of the object Measure-Command returns.

If we need to reference total seconds, we will reference the TotalSeconds property. We could assign the output of Measure-Command to a variable and reference all properties.

$slow_performance = Measure-Command -Expression { 0..10000 | ForEach-Object { $arr01 += $_ } }

Let us now use the quicker way of adding elements to an array by using an ArrayList and see how fast that is.

Example Code:

$arr01 = [System.Collections.ArrayList]@()
$fast_performance = Measure-Command -Expression { 0..10000 | ForEach-Object { $arr01 += $_ } }

$fast_performance

Output:

Days              : 0
Hours             : 0
Minutes           : 0
Seconds           : 7
Milliseconds      : 346
Ticks             : 73465163
TotalDays         : 8.50291238425926E-05
TotalHours        : 0.00204069897222222
TotalMinutes      : 0.122441938333333
TotalSeconds      : 7.3465163
TotalMilliseconds : 7346.5163

We can also check the runtime of a PowerShell file (.ps1) using the Measure-Command.

Example Code:

Measure-Command { .\checkdrives.ps1 | Out-Default }

Output:

Days              : 0
Hours             : 0
Minutes           : 0
Seconds           : 0
Milliseconds      : 30
Ticks             : 308166
TotalDays         : 3.56673611111111E-07
TotalHours        : 8.56016666666667E-06
TotalMinutes      : 0.00051361
TotalSeconds      : 0.0308166
TotalMilliseconds : 30.8166