Mac OS X Mavericks might have lots of fantastic tech to save battery life and be more efficient with RAM and processor usage, but your data bill might suddenly be sky-high.

With the latest version of Apple’s desktop operating system the default behaviour in the Mac App Store is to automatically download and install updates from the Mac App Store, including those for iTunes – a piece of software that’s updated quite often, with a download size of between 40 and 120MB. If left enabled, the auto update feature could soon leave you hitting your download cap for the month.

The problem isn’t so much the auto updates – it’s a convenience feature that people are likely to use – it’s the fact that Mavericks does it silently. Previous versions of OS X would prompt users when updates were available to be installed, but Mavericks removes those notifications. The only way of knowing that apps have been updated is by visiting the Launchpad and looking for sparkling icons (indicating a new or updated app), or opening the Mac App Store and clicking on the update tab, where recently-updated apps show up.

The behaviour is slightly different for iPhone, iPad, and iPod touch users. In iOS 7 Apple also introduced an auto-update feature that allows applications to update automatically, however this is only done when you’re connected to a wireless network. This avoids costly 3G data bills when all of your games and photography apps end up downloading their updates without consent.

Mac OS X machines are either connected to the network using a cable or wireless, and treat all internet connections equally. As a result, the OS doesn’t know when users have 3G connections or have ADSL accounts, either of which could have a small cap.

To disable automatic app updates in Mavericks, simply go to System Preferences -> App Store, and deselect the appropriate options.