Disable Windows power throttling on VirtualBox executables

VirtualBox-Disable-PowerThrottling.ps1

<#
 .SYNOPSIS

  Disable Windows power throttling on VirtualBox executables.

  Copyright (c) 2024, Thierry Lelegard
  BSD-2-Clause license, see https://opensource.org/license/BSD-2-Clause

  The problem: On some recent Intel chips such as the Alder Lake family,
  there are two types of cores: P-cores and E-cores. P-cores are designed
  for performance and E-cores for power efficiency. As a rule of thumb,
  "foreground" processes, typically manually run with a window on screen,
  run on P-core while "background" processes run on E-cores. Using VirtualBox,
  when a virtual machine is started from the command line, headless, it is
  considered by Windows as a background process and ends on E-cores. Not only
  the VM has lower performances, but some VM don't even boot for some unknown
  reasons (Fedora sometimes hangs during boot)

  The solution: Disable "power throttling" on all VirtualBox executables.
  Thus, all these executables won't be candidate for E-cores and will run
  on P-cores.

 .PARAMETER NoPause

  Do not wait for the user to press <enter> at end of execution. By default,
  execute a "pause" instruction at the end of execution, which is useful
  when the script was run from Windows Explorer.

#>
param([switch]$NoPause = $false)

# VirtualBow installation:
$VBoxRoot = "C:\Program Files\Oracle\VirtualBox"

# Do we run as administrator?
$IsAdmin = ([Security.Principal.WindowsPrincipal][Security.Principal.WindowsIdentity]::GetCurrent()).IsInRole([Security.Principal.WindowsBuiltInRole]::Administrator)

# All VirtualBox executables.
$Execs = Get-ChildItem "$VBoxRoot\*.exe"

if ($Execs -eq $null) {
    Write-Output "Error: no .exe found in $VBoxRoot"
}
elseif (-not $IsAdmin) {
    Write-Output "Must be administrator to continue, trying to restart as administrator ..."
    $cmd = "& '" + $PSCommandPath + "'" + $(if ($NoPause) {" -NoPause"} else {""})
    Start-Process -Verb runas -FilePath PowerShell.exe -ArgumentList @("-ExecutionPolicy", "RemoteSigned", "-Command", $cmd)
}
else {
    # Execution as administrator, we can proceed.
    $Execs | ForEach-Object { powercfg /powerthrottling disable /path $_.fullname }
    powercfg /powerthrottling list
}

if (-not $NoPause) {
    pause
}