How To Measure What’s Inside Your Mac’s Hard Drive.

I have some bad news. Your hard drive is filling up. Fast. Mine, too. I have two main Macs that I use daily. Both have large hard drives. So I thought.

My older Mac is used for email, browsing, iTunes, iPhoto, and odds and ends utilities. Guess what? 320 gigabytes is not enough. Now I know why.

I happened to glance down at the bottom of my Mac’s Finder and noticed that I had barely 60 gigabytes left out of 300 gigabytes. Where did all that extra space disappear?

Granted, both my Macs are set up about the same, though my larger and faster Mac has larger and faster hard drives, because it stores more files. But my everyday Mac was quickly running out of disk drive space. Why?

To find out what was happening on my Mac’s hard drive, I opened up one of my favorite utilities. WhatSize doesn’t get used often, but it’s a big help in telling me where files are, and how large the files are.

Guess what? There are more files on my Mac than I thought and the file sizes are larger than I thought.

My biggest disappointment is that WhatSize is now true shareware. It used to be free. Now it nags for money. But it still works fine, though a shade overpriced at $12.95. If you have plenty of files on your Mac and limited disk drive space, this is a good utility to have around.

WhatSize is simple. It scans your Mac’s hard disk drive for files, then it lists, in that ever wonderful column view, all the files and directories and their respective sizes.

Since it uses column view, finding the drive space hogs is easy.

As you’ll find out, a 300 gigabyte hard drive starts Mac life at less than 280 gigs after formatting. I promise not to sue the drive makers for false and deceptive advertising.

Remember, this particular Mac does double duty. It’s what I use for everyday work so it has plenty of applications, and I have it set up to run as a backup to my main workday Mac, which has even larger hard drives and more files.

WhatSize takes a minute or so to scan your Mac’s files then put them into a nice hierarchical listing in column view. Here’s what I found.

My User folder has nearly 140 gigabytes of files. Not bad for only two users, me and the administrator (no extra files). The Mac’s Library folder has nearly 70 gigabytes of files, the Applications folder has 12 gigabytes of files.

The Mac’s System folder and all other folders have barely 6 gigabytes total. No wonder Apple can squeeze OS X into an iPhone and iPod touch.

My User folder’s user has almost 50 gigabytes of iTunes files. Damn those movies and TV shows. Photos in both iPhoto and Aperture take up another 40 gigabytes. Odds and ends videos and Documents take up another 40 gigabytes. Ouch.

The problem is that those are files I need, I back them up, I cherish them, prune them, nurture them. There’s not much to get rid of.

My Mac’s Library folder is loaded with files. Application Support takes up over 30 gigabytes. The Audio folder is nearly 25 gigabytes, most of which is Apple Loops. There’s almost 3 gigabytes of files in the Printer folder. I have two printers.

The rest of the Library folder is filled with various and sundry files that do this or that and don’t take up much space. So the real killer is the Application Support folder.

As you might suspect, the bigger files are duplicates of FinalCut Studio—LiveType, DVD Studio Pro, and so on. Those I keep running on this Mac as a backup for my larger, faster Mac.

The Applications folder is next. There’s not much pruning to be had here. Adobe’s Acrobat takes up the most space at almost a full gigabyte. Acrobat came with Photoshop CS3 Suite, though I seldom use it. I use Apple’s Preview instead.

WhatSize does a great job of making your Mac’s files visible, including invisible files, which are plentiful on your Mac. As I scoured my Mac for superfluous files, one thing became quite clear. There wasn’t much I was willing to throw away.

That means there’s only one direction to go.

The conversation at home will go something like this. “Honey, my main Mac’s hard drives are about full so I’m in danger of losing valuable data. I’m not sure if I want to go to all the trouble and expense to upgrade all the hard drives, or simple get a new Mac Pro which can easily store all our music, movies, photos and files for years to come.”

Thank you, WhatSize, for another job well done. That’s $12.95 well spent.