Quick tip: Pre-compile assemblies to improve PS startup time

Just a quick reminder for myself.

$FrameworkDir=[Runtime.InteropServices.RuntimeEnvironment]::GetRuntimeDirectory()
$NGENPath = Join-Path $FrameworkDir 'ngen.exe'

[AppDomain]::CurrentDomain.GetAssemblies() |
  Select-Object -ExpandProperty Location |
  ForEach-Object { & $NGENPath """$_""" } 

Powershell loads and JIT compiles tons, and tons, and tons of stuff. This takes a lot of excessive CPU cycles and disk I/O.

ngen.exe (Native Image Generator) can be used to precompile the assemblies that Powershell loads during startup.

Source:
http://serverfault.com/questions/761301/calling-powershell-exe-is-extremely-slow