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Q. Is my hard drive really full already?

Published May 2011

My MacBook Pro has a 500GB hard drive. Although I only bought it in August, I'm already being told that it's full. I have the most recent version of Logic Studio loaded onto it, along with the Snow Leopard operating system. I also currently have some QuickTime files that I'm using for editing that were converted from DVD to M4V format.I can't believe that, even using the machine for these sorts of applications, I've filled the hard drive. I did free up a significant number of gigabytes simply by emptying the Trash, but is there something that I need to run to clear away some fluff files?

Also, I wonder if I should move the movie files onto my G‑Tec 1TB drive, which I use for Time Machine backups. Does this sound like a good idea?

Via SOS web site

SOS contributor Mike Watkinson replies: The latest version of Apple's Logic Studio, v9, has an install size of approximately 55GB, depending on which options you tick while installing, and Snow Leopard, as installed on your MacBook Pro, will be around the 8GB mark. Doubtless you have other applications installed, but only software instruments like BFD2 are significant in this context (BFD2 is around 55GB for the full installation). It's important to remember that a hard drive with a quoted size of 500GB will reveal itself to have only around 465GB of space in Disk Utility. This is a result of a mathematical anomaly, exploited by hard‑disk vendors, caused by the fact that there are 1024 bytes in a kilobyte, 1024kB in a MB, 1024 MB in a GB, and so on. Even so, with Logic Studio installed, you should have at least 350GB.

Your first, and simplest, port of call when checking used capacity on your hard drive should be to access the 'Info' from your Finder's File menu.Your first, and simplest, port of call when checking used capacity on your hard drive should be to access the 'Info' from your Finder's File menu.

The movie files you mention could be part of the issue. Ripping a DVD to QuickTime's M4V format can create file sizes of between 450MB and 1.2GB, depending on the length of the film. This is relatively small in this context, but if you import to a movie-editing application and choose to 'optimise' the file size on import (for example, you can choose 'Full Original Size' from iMovie's 'Optimize the Video' options when importing) this can increase the file size by up to 10 times, so what was 1.2GB becomes 12GB. You would still need to have more than 25 files of this size to fill up the available space completely, though.

However, it is still difficult to guess what might be the cause of the problem. It has been reported that certain log files can grow in size, but certainly not to the extent you describe. The first step in investigating would be to use the Finder to help you identify large files. Movie files typically reside in the Movie files folder in the Home folder, so you could start by selecting the Home folder (make sure nothing else is selected) and pressing Command‑I (or choosing 'Get Info' from the Finder's File menu). This will list the information for that file or folder. If it's very large, drill down into the Home folder until you find the rogue files. It is important to remember that moving a file to the Trash does not delete it from the hard drive. As you have discovered, you will only reclaim the space when you empty the Trash!

If this process sounds long‑winded (it can be!), I would recommend that you use one of the available utilities to check the contents of your hard drive. WhatSize (from has a Finder‑like interface that lists the size of every file on your Mac. However, you may prefer a graphical view, in which case the free GrandPerspective (from will analyse your disk and provide a pictorial representation of the relative size of all files.

DiskRadar (from is a new addition to this field and, although it isn't free (the Lite version sells for $12.95), as well as scanning your disk, it can show you the largest files in sequential order, highlight rarely used files, perform disk‑health diagnostics, and let you clean the disk up from within the application. It is very fast compared with other options, and the extra facilities make it well worth the money if you are keen to keep track of hard-drive usage.

DiskRadar (from <Link></Link>) shows a graphical representation of file sizes and usage.DiskRadar (from shows a graphical representation of file sizes and usage.Moving the rogue files to another hard drive is a good solution if you wish to keep working with them, but not if that drive is set up as a Time Machine disk. You could partition the external drive and use part of it as temporary storage, and part for Time Machine backups, but given the relatively low cost of hard drives, it might be better to invest in a separate external drive for video (and audio) editing.  

Published May 2011