I just installed Snow Leopard on my iMac, doing a complete wipe and re-install of the hard disk drive–something that should be done with a computer every year or two anyway (more often if you use your computer more like I do). And the change is extremely noticeable.

First, I should say that I had not wiped the disk and reinstalled the OS for a few years, so that makes a lot of the difference right there. Crashes, errors, and just plain hard use over a few years will introduce enough glitches in the OS and with the hard disk that will slow your computer down significantly enough. Still, I don’t remember it being this fast before. I know, subjective, but still. Safari pages load fast, very fast indeed.

One of the first things to note about Snow Leopard is the footprint: Apple claims that you’ll save 6GB of disk space because they have slimmed down the system so much. When I installed, I customized it so that it would add in all printer drivers plus other software that Snow Leopard does not install by default, so as to remove any slimming-by-defeaturing. I started out with a hard drive with 219.5 MB of free space. After Snow Leopard was installed, it showed that I had 243 GB of free space. Whoa! Did I just get 24 GB of extra drive space?

Alas, no. But I did get the advertised 6GB. With Snow Leopard, Apple has also changed the way hard disk drive space is reported: in Snow Leopard, they switched from base two (binary) to base ten counting. When you buy a 250GB hard drive and plug it in to your computer, it only shows something like 238GB available; this is due to the difference in counting systems. Now that Snow Leopard uses base ten, just like the hard drive sellers, when you plug in a 250GB hard drive, it’ll show 250GB available.

That’s where I got the bulk of my “extra space” from, and this difference became clear with a simple test: I shut down my Snow Leopard iMac, tethered it to my non-Snow Leopard Macbook Pro, and held down the “T” key on the keyboard while restarting the iMac, making it start up (in just a second or two) as an external drive to my MBP. And on the MBP, the free disk space is listed as 225.14GB–almost exactly 6 gigabytes lighter than it was before I installed Snow Leopard.

So far, I have not had much chance to test the whole system out. Startup certainly goes a lot faster, and the icon-resizing slider is very cool. I have not used the new Exposé features much yet, but they seem to work as advertised. I tried out the new system-wide autotext replace feature (type in a text string and have it be replaced by another), and it works, though disappointingly weakly. It does not work in some places (such as, disappointingly, any text window or box in Safari), nor does it not allow you to control how it swaps the text (it only swaps after a space has been typed). It’s kind of a very weak version of the text-swapping software I have used–and suspect will no longer work in Snow Leopard.

And that leads up to the big thing, the reason why I might not be installing Snow Leopard on my Macbook Pro just yet: some software doesn’t work yet. I have become heavily dependent on two things: my autotext replace utility and PithHelmet, my ad blocker for Safari. PithHelmet doesn’t work either–I tried to install it, but apparently SIMBL doesn’t work in Snow Leopard yet. And for me, that’s a big deal–after having blissfully quiet web pages for so long, going back to pages filled with all those dancing, flashing ads is a jarring experience, not to mention an incredibly annoying one.

I’ll report more on Snow Leopard after I test it out some more, but it may be a week or two–Apple is taking in my iMac this week, something I’ll cover quickly in my next post.