Poor human's hexdump in ps. Works but stupid slow

gistfile1.txt

$filePath = "D:\test_binary.exe"
$bytes = [System.IO.File]::ReadAllBytes($filePath)

$hexLines = @()
$asciiLines = @()

for ($i = 0; $i -lt $bytes.Length; $i += 8) {
    $lineBytes = $bytes[$i..($i + 7)]
    $hexLine = -join ($lineBytes | ForEach-Object { " {0:x2}" -f $_ })
    $asciiLine = [System.Text.Encoding]::ASCII.GetString($lineBytes)

    $hexLines += $hexLine
    $asciiLines += $asciiLine
}

for ($i = 0; $i -lt $hexLines.Count; $i++) {
    Write-Host "$hexLines[$i]|$asciiLines[$i]"
}