With version CS6 (aka v.16) Adobe Illustrator is a 64bit application. But what exactly does that mean? Sometimes I think it's like that SNL spoof of Verizon's marketing around 4G LTE.
Truth be told, a 64bit version of Illustrator means a lot. Not necessarily because of what 64bit actually *IS*, but really because of what Adobe had to do in order to move Illustrator to 64bit.
Let's start with the basics.
Your computer has two kinds of memory—hard drive space and something called RAM. The hard drive space is storage—like a drawer in your desk. The RAM is like your desktop. A computer can only process information using RAM (what's on your desktop). So for example, when you launch Illustrator, your computer goes to your hard drive and copies that information into RAM so that you can work with Illustrator (like pulling a file out of the drawer and placing it on your desktop so that you can work with it). As you create and open more documents, your desktop (RAM) becomes filled. If you run out of RAM, your computer must "clear space" by temporarily copying stuff to your hard drive so that it can work on what you're asking for. This is why if you have a lot of applications and documents open at once, you could see your system slow to a crawl.
In theory, the more RAM you add to your computer, the larger of a desktop area you have, or the more capacity your computer has to work with documents and applications without having to shuffle information between your RAM and your hard drive. Here's the thing though: while your computer may have the capacity to install 8GB or 16GB (or more) of RAM, a 32bit application can only see (or "address") a maximum of 2GB or RAM (in some circumstances, 3GB of RAM). In contrast, a 64bit application has the ability to address as much RAM as you can squeeze into your computer (theoretically).
So as an example, say you have a computer with 16GB of RAM. And say you were using Illustrator CS5, which is a 32bit application. If you are working with complex files, Illustrator is only able to use a maximum of 3GB of your RAM. With Illustrator CS6, which is a 64bit application, on that same computer, Illustrator would be able to address all the available RAM that you have on your system. Depending on the situation, this could speed up processing time significantly. Of course, this is assuming you have a lot of RAM installed on your machine (at least 8GB), and also assuming that you're working with a lot of files or complex ones.
But as I mentioned earlier, the sheer fact that Illustrator is 64bit, doesn't actually make the application faster or better in any way. It simply means that Illustrator has a bigger playground to play in. The big difference is that in order to make Illustrator a 64bit application, Adobe had to do some work. Wait, let me rephrase that—Adobe had to do a significant amount of work. It's the result of this work that—in my opinion—makes Illustrator CS6 a must have upgrade. In other words, even if CS6 had no other additional features other than this work, I'd recommend the upgrade.
So what are the benefits of the work that went into making Illustrator a 64bit application?
Stability
Most crashes occur when a computer runs out of memory (RAM). In theory, a computer should never run out or RAM because when it sees that it doesn't have enough, it temporarily offloads some information to your hard drive to make space. A computer program usually keeps track of how much memory it uses so it knows how much is left when it's about to perform complex functions. If there isn't enough, and your computer can't make enough room with the RAM that you have, you might get an error (along the lines of "there's not enough RAM to complete this operation").
Adobe Illustrator just turned 25, and when I left the team back in 2004, the program contained over five million lines of computer code. Just like an old house is drafty, a computer program of that size can often "leak" memory. That is, the program may use memory to perform a function, but then "forget" to release that memory when the function is complete. So the computer system thinks the memory is available, but it really isn't. So when Illustrator later tries to calculate if there's enough RAM to perform a function, it runs out of memory during processing (kinda like Wile E Coyote running off a cliff before realizing there's nothing beneath his feet). This causes a crash.
In order to make Illustrator 64bit, Adobe had to rewrite a LOT of code. Tons of memory leaks were fixed, which results in a much more stable environment. This, coupled with the fact that Illustrator can use all of the memory in your computer, translates to a far more reliable experience. So in this case, a 64bit version of Illustrator will likely mean you'll no longer see random crashes or out of memory errors. So while it may not always be faster, it is stable and reliable.
Experience
While everyone will instantly notice the newer "dark" user interface in Illustrator CS6, few will appreciate what it really means. Illustrator's user interface was built upon a framework that was 32bit. So in order to get to 64bit, Adobe had to use a newer framework. This translates to two main benefits for us: the newer framework supports more things (i.e. the ability to edit text inline in a panel); and the fact that Adobe had to rewrite EVERY panel and EVERY dialog box in the application.
For example, if you're on a Mac and want to cycle through fonts, you previously had to choose a font from the popup font menu with your mouse each time. Now, you can simply highlight the Font field and tap the up and down arrows to cycle through (and preview) different typefaces. If you want to rename a layer, an artboard, a swatch—you can do that simply by double-clicking on the name in the panel itself—without having to bring up a separate dialog box.
Adobe also had the opportunity to modify panels and dialog boxes. So for example, the Preferences dialog box is much easier to navigate, and the Color panel has a much larger area to sample colors from. Overall, you'll see that the user interface isn't just a darker color (which can be adjusted to a lighter color of course), but that it is silky smooth and has that new car smell.
Future
The Illustrator team has always wanted to add newer features, but was often held back by the older architecture. By laying the groundwork with a modern 64bit architecture in CS6, Adobe is paving the way for what they can do in the future. You can almost think of Illustrator CS6 as a foundation that Adobe can use to build more powerful features upon. For example, many are familiar with the crash-protection feature in InDesign. You can never lose your work in InDesign. Wouldn't it be awesome to have such a feature in Illustrator? I think it would. But Adobe couldn't even think about adding such a feature to Illustrator without first building a foundation for such a feature. So the work that was done in Illustrator CS6 means that in future version, Adobe has fewer roadblocks and more opportunities to build the features we are asking for, and the features that they are continuing to dream up.
Hopefully, this article gives you a better understanding of what a 64bit version of Illustrator means to you. Got questions? Leave a comment below and I'll do my best to answer them.