Using SilentKnight to download updates

Many of us are keen to download and install macOS and other updates as promptly as we can. This article explains how my free app SilentKnight can help you do that, and what it can’t do.

By default, whenever you run SilentKnight it checks with Apple’s servers to detect if there are any updates available for that Mac. It does so using the command
softwareupdate -l --include-config-data
(except on El Capitan, where it has to run softwareupdate -l instead). There’s no magic to this, and it’s exactly the same command that you could type in for yourself in Terminal.

That command causes your Mac to try to connect to Apple’s update servers, and ask for a list of any and all system and security updates due for that Mac. Although this should be essentially the same as when you open the Software Update pane, it normally proves more effective in obtaining information about updates available.


SilentKnight isn’t intended to be used to download and install larger updates, such as those for macOS, but for smaller and more common updates such as those to MRT and XProtect, which are normally its bread and butter. When SilentKnight advises you that a large update is waiting, I recommend that you open the Software Update pane and use that to download and install that update.

It’s common experience that checking for updates using SilentKnight can lead to Software Update recognising an update when previously it didn’t detect one. This is a quirk of the system, and probably results from the behaviour of the Software Update pane, which may not check for updates every time that you open it. SilentKnight, though, always checks for updates, unless you set it not to check (an option explained in its Help reference).

What I suggest is:

  • If you suspect there’s an update available, or just want to check, open SilentKnight and let it check for updates as usual.
  • If SilentKnight reports only small security data and similar updates, click on the Install all updates button to download and install them.
  • If SilentKnight reports one or more large updates, such as a macOS update, open Software Update and use that to download and install the updates.
  • If SilentKnight reports that there are no updates, or the one you’ve been expecting isn’t detected, quit the app and check again a bit later.

For macOS updates the alternative is to download the full installer rather than the update. That’s certainly going to be far larger, typically more than 13 GB, and slower to install than the update. There’s also the risk that the full installer won’t be able to join the System up with your existing Data volume, forcing you to migrate instead of updating. If you prefer, you can always perform a full macOS install in Recovery mode, although once again there’s the risk that could turn into a migration.

If you’re really keen to get your Mac updated, it can sometimes be frustrating when you know that there’s an update available, but neither SilentKnight nor Software Update are able to find it. That’s normally because Apple’s servers aren’t currently offering it to your Mac. That may be a regional matter: updates often become available at slightly different times around the world, which may be deliberate on Apple’s part, to stagger the load on its servers. It could also be the result of server problems, which do occur sometimes. Rather than trying to game the system, it’s far better to leave it an hour or so and check again, until the update does become available.

SilentKnight can only do what’s supported by the softwareupdate command. To be explicit, SilentKnight can’t:

  • download software which isn’t already listed by SilentKnight as being available;
  • download an update which Apple hasn’t yet released;
  • download a firmware update;
  • update your Mac’s firmware;
  • download the full installer of any version of macOS;
  • save downloaded updates to macOS in any usable form.

May all your updates be happy and successful.