With almost all new computers within the past few years having 64-bit CPUs and 64-bit versions of Windows, a natural question people have is whether they need (or have) to use the 64-bit versions of their favorite programs (such as Microsoft Office). Luckily, today’s installment of Ask The Geek has the answer.

CPU MacroFirst though, a little bit of history: when talking about 32-bit and 64-bit, we’re referring to the maximum size of a number that the CPU can hold at once. Think of it as being like the spaces you sometimes see on forms or credit card offers, where there are a fixed number of spaces for you to enter the letters of your name or address.

With a 32-bit CPU, there are only 32 spaces, and with the 64-bit CPU, there are (naturally) 64 spaces. Since every “spot” in your computer’s memory is numbered (computer people will say it’s “addressed”), the CPU can only handle as much memory as the biggest number it can fit into its limited number of spaces.

For 32-bit CPUs, that equals 4 GB of RAM (or 4 billion “bits” of memory). Up until just a few years ago, having this much memory in your computer was extraordinarily rare – something that only super computers or big servers had. Today, however, it’s likely your smartphone has more than that much memory in it.

For 64-bit CPUs on the other hand, that equals 16 exabytes – that’s 16 quintillion “bits” of memory!

OK – so we know that computers with 64-bit CPUs can use (or “address”) more memory, and that’s why 64-bit operating systems (e.g., Windows 7 64-bit) that can take advantage of that extra memory are the way to go. So where does that leave us when it comes to the ordinary programs we use every day – should they all be 32-bit or 64-bit? Or does it even matter?

Well, consider that 32-bit computers and software have been around for a very long time (in computer terms) – since at least 1995 for most people. (Remember Windows 95? That was the first 32-bit version of Windows most people used.) Also consider that forcing people to switch every single program they use to a corresponding 64-bit version just isn’t going to happen. (Nevermind that for many programs, there isn’t even a 64-bit version available at all!)

So all 64-bit computers can also run 32-bit programs just fine – they have to, or else no one would bother using them, despite the advantages. After all, nobody wants to have to buy all new programs and start over from scratch. However, 32-bit programs on 64-bit computers can’t use more than 4 GB of RAM at once – but that’s OK, because they’ve never been able to use more than that much RAM to begin with, so nothing gained, but nothing lost, either.

So, you can use a 64-bit version of Windows on your 64-bit computer and have more than 4 GB of RAM, and although no one 32-bit program is going to use it all at once, this does mean you can run several programs all at once, and never have to worry about running out of memory.

This is where we come back to our original question – do you need (or have) to use the 64-bit versions of your favorite programs?

The answer, as you could probably guess by now, is NO.

The only reason you would use a 64-bit version of a program is if that program needed to use an absurdly large amount of memory – and there are very few situations in normal home or office use where you would encounter a situation like that.

Typically, the types of situations that would absolutely require a 64-bit version of a program (and the larger amount of memory they can use) are things such as:

  • Huge, complex image files in Photoshop might possibly require more than 4 GB of memory
  • Very large video editing or rendering projects
  • Complex spreadsheets with millions of rows/cells
  • Very large database programs

Furthermore, if you already have a 64-bit computer, chances are most of the programs you’re using right now are mostly still 32-bit – for example, the web browser you are using to read this article is almost certainly a 32-bit program. And even for those programs which do come in both 32-bit and 64-bit editions (e.g., Microsoft Office 2010, or Adobe Photoshop), the 32-bit edition is almost always the default.

But what’s the harm in using the 64-bit version, you might ask? After all, bigger is better, right?

Well, actually in this case, that’s not entirely true. Due to handling very different sizes of information, 32-bit and 64-bit programs can’t really “talk” to one another very well, and so if you’re using a program that talks to other programs, or uses “plugins” or “add-ins” (and you’d be surprised how many programs you use on a daily basis are like this), you must make sure that your program and the other programs it needs to talk to, as well as any plugins or add-ins are all the same “bitness” (that is, all either 32-bit or 64-bit).

So, in most cases it is actually better to stick with 32-bit programs, simply because there’s no actual advantage to the 64-bit version (except for some very rare cases), and most other programs are also 32-bit, and you don’t want to “break” the ability of your program to talk to other programs or use plugins and add-ins.

I hope this has helped shed some light on a somewhat confusing and often misunderstood topic. So now, if you ever have the choice between a 32-bit and 64-bit program, you’ll be in a better position to decide for yourself which one you really need.

[note class=”email”]Have a question for the geek? Send it to us at askthegeek@turbolaw.com![/note]

CPU photo by Lemsipmatt. RAM photo by ReillyButler.