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Hypnosis

macrumors member
Original poster
Jun 16, 2015
40
4
New mac user here. I just wanted some clarification on what updates exactly do (storage wise). Do they replace and update existing files, or do they add onto the existing files? Frankly put, if I have an application that uses 1.5GB and there's an update available that is 800MB, will the application be 2.3GB after updating?
 

chrfr

macrumors G5
Jul 11, 2009
13,548
7,075
I have an application that uses 1.5GB and there's an update available that is 800MB, will the application be 2.3GB after updating?
It's impossible to answer with certainty. Some updates will be large, but will replace existing resources in the application, while other updates may add new files that increase the application size.
 

Hypnosis

macrumors member
Original poster
Jun 16, 2015
40
4
It's impossible to answer with certainty. Some updates will be large, but will replace existing resources in the application, while other updates may add new files that increase the application size.

I was under the impression that this would be the case. I'm assuming majority of the iOS updates are the latter?
 

chrfr

macrumors G5
Jul 11, 2009
13,548
7,075
I was under the impression that this would be the case. I'm assuming majority of the iOS updates are the latter?
Again, the same factors apply for iOS too. Both OS X and iOS use delta updates for applications.
 

Starfia

macrumors 6502a
Apr 11, 2011
950
664
Applications are a collection of files delivered as a bundle. In OS X, you can go into your Applications folder, right-click on anything, choose "Show Package Contents" and actually see the files. They usually include some code files (the actual programming), images used in the applications interface, sounds, fonts, or whatever else.

When a developer updates an application and you install the update on your computer, you're essentially replacing the entire bundle with the new version of the bundle. The new version might mean a simple bug fix (like, a slight change in one of the programming files) or a dramatic increase in files (like the addition of 100 new stock photographs). In any case, the total size of the application on your hard disk after the update is complete should equal the total size of only the newest version of the bundle. (As Gav2k mentioned, the system is capable of doing some clever things like noticing only which portions of the app have actually changed, and only using the bandwidth necessary to download those when you install an update.)

It's tough to guess whether "most" of application updates involve added resources – I'd guess not, since so many updates are quick maintenance updates. You can probably infer about this by reading the description of the latest version for that app (e.g. "this update contains several bug fixes").

I think you might be asking how that size is described when you're inspecting it in the App Store, and that I'm not sure about.
 
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