Should I get the 64 bit version of Windows?

I've covered some of this in an earlier article, Are 64-bit PCs more secure than 32-bit machines?. (A little, for now. )

To summarize some of the differences between 32 and 64 bit processors:

• 32 bit versus 64 bit really just means the size of the biggest integer number that the CPU can work on. In 32 bits that's 4,294,967,295, and in 64 bits it's 18,446,744,073,709,551,615.

• Similarly, a 32 bit computer can theoretically access 4,294,967,296 bytes (4 gigabytes) of RAM, while a 64 bit machine would be able to access 18,446,744,073,709,551,616 bytes (over 17 billion gigabytes, or 16 exabytes).

• Some 64 bit processors have the option of loading data from memory 64 bits (or 8 bytes) at a time instead of 32 bits (4 bytes) at a time. Thus it's possible for data access to be twice as fast if the computer's motherboard and memory supports it.

Those are the major differences. What they typically translate to in more useful terms is that it's possible for a 64 bit processor to do more work in less time than a 32 bit processor.

"Possible" is an important word here.

Most basic is that you need an operating system that runs in 64 bits, like the 64 bit versions of Windows. This is a start, and Windows can already make use of the 64 bit architecture to improve its performance, particularly in high-load scenarios. Ideally, you also want your applications to take advantage of 64 bits, in particular those applications that could really benefit from it - those that are CPU and memory-usage intensive.

The biggest drawback you'll find is exactly the scenario that you mentioned: drivers. Vista already has a mediocre track record when it comes to compatibility with older drivers, particularly printer drivers, even staying in the 32 bit world. Windows 64 bit has made that worse in that existing 32 bit drivers typically don't work - new 64 bit drivers must be provided. If they're not, you're likely to be out of luck. Reports on driver availability vary, but particularly for older hardware I wouldn't be particularly hopeful.

I've also heard, but not confirmed, that the size of executable files, ".exe" and ".dll" files, has also increased - hence it's likely that you'll also need some more disk space for your 64 bit operating system and tools. Fortunately, disk space is exceptionally cheap these days, and this is easily handled.

Ultimately, my take on it is that certainly for the average computer user, and perhaps even the advanced computer user, it's not yet time to go 64 bits. Most people do things that are handled quite will with 32 bit processors. Let's face it, word processing, web surfing, picture viewing and email are not processor-intensive applications, and the 32/64 but difference likely wouldn't be noticed.

Where does 64 bit make sense?

It makes sense mostly in memory-intensive applications. As we've discussed before, you can only put 4 gigabytes into a 32 bit machine (and even then, not all of that will be used). If you absolutely need more RAM then a 64 bit machine is the way to get it. The catch is that today, still, most people do not need more memory. The types of situations that could benefit would include heavily used servers and applications which process lots and lots of data - for example video editing and encoding, assuming that the video editing program was itself also 64 bit enabled.

64 bits will happen, but it's not yet time for average users to jump on it.

(If you're curious, you can see whether your processor will support 64 bits by running Securable, a free utility from GRC. That won't tell you whether your motherboard supports its 64 bit data transfers, but will tell you if your machine is even capable of running 64 bit Windows.)

I'd invite people who are running 64 bit Vista to share their experiences in the comments.