64-Bit Computing: The Next Big (Confusing) Thing

Erik Lustig's mom called him recently in a bit of a panic. She'd been in a retail store shopping for a computer and the sales guy asked her whether she wanted a 32-bit computer or a 64-bit computer, and of course he was pushing the 64-bit machine, because it's faster. (And more expensive.) Luckily for Mrs. Lustig, her son is a senior product manager at Microsoft, and he happens to work on operating systems. "I told her, Mom, if you drove a VW Beetle, or a Camry, or a BMW, you would drive the same way. You'd never exceed the speed limit. So buy the cheapest one. Buy a 32-bit machine," Lustig recalls.

Ah, but then came the kicker─Dad would be using the machine as well, and Dad is an engineer and runs some specialized applications that are math-intensive. "I told her, if that's the case, if Dad's going to use it for engineering work, then go for the 64-bit and max out the RAM. In other words, if you're buying for you, buy the Camry. If you're buying for Dad, buy the Bimmer."

Guess what? If you're going out to buy a new PC this fall, you're going to be hit with the 64-bit question, just like Mrs. Lustig was. Therefore, you'll need to know what 64-bit computers are, and what they do, to determine whether you need one.

Here's the deal. The computers that most of us run today manage data in chunks that contain 32 bits (0s and 1s) of information. But the next big thing from PC makers is machines that manage data in chunks that each contain 64 bits of information. That means they have a microprocessor that moves data in 64-bit chunks, and they run a 64-bit version of the Windows operating system. Their cheaper counterparts, 32-bit computers, address data in chunks that contain only 32 bits and run a 32-bit version of Windows.

The big difference involves how much RAM (memory) the system can support.  A 32-bit machine can handle a maximum of 4 gigabytes of memory. That's a pretty colossal amount of memory. Not long ago, 4 gigs seemed crazy and excessive. Now some PC makers feel it's not nearly enough. They want to build machines that contain even more memory, because this speeds up the performance of some applications, especially graphics-intensive ones like video editing and photo editing, or hard-core videogaming.

To build a system with more than 4 gigs of RAM, you need to have a 64-bit microprocessor and a 64-bit operating system. So that's what everyone is doing now. The fact is, 64-bit computing has been around for a while, but nobody really cared. Microsoft started shipping a 64-bit version of Windows in 2001. AMD and Intel have been making 64-bit chips for years. Yet at the end of last year only 5 percent of desktop PCs were running 64-bit Windows, according to Microsoft. However, that is all about to change, and in a big way: this holiday season, as Microsoft rolls out its new Windows 7 operating system, the software maker expects half of all PCs sold to be 64-bit machines.

Right now we're talking about 4 to 8 gigs of RAM on a desktop machine. A few years out we could be seeing machines with way more than that. The limit for Windows 7 is 192 gigs, and the theoretical limit for a 64-bit machine is a number so big that we won't ever have to worry about it in our lifetime. Or so we think today. At one point everyone thought 32-bit computers addressing 4 gigs of RAM provided more headroom than anyone would ever need.

What will those machines be able to do in five years? Perhaps they will render a movie instantly, instead of needing an hour or more, as is the case today. In the computing industry, there's a constant demand for more power, and no matter how fast the hardware and operating systems get, software makers keep finding ways to exploit that power and gobble it up. "The videogaming industry is loving the move to 64-bit. They can create far more immersive environments, the most realistic games ever. Games today are already over the top, and there is no end in sight," Lustig says.

One caveat: you might be thinking that bigger is always better, so when you go to the store you'll just buy a 64-bit machine and be done with it. But there is a potential drawback to a 64-bit machine─if you skimp on the RAM. The 64-bit Windows operating system is larger than the 32-bit version. On a machine with less than 4 gigs of RAM, the 64-bit operating system could run slower than a 32-bit version─o if you're using less than 4 gigs, you should stick with 32-bit Windows.

Also note: none of the above applies to Apple, because if you buy an Apple computer you don't have to worry about choosing an operating system. All of Apple's machines ship with the same operating system, and there's only one version. The latest one is OS X Snow Leopard, and it's a "hybrid," meaning parts of it are 64-bit and parts of it are 32-bit. Apple touts the simplicity of having only one operating system. Microsoft, for its part, claims its approach gives greater choice to customers and business partners. Microsoft also touts its 64-bit operating system as a "true, native 64-bit" operating system, versus the "hybrid" approach at Apple.

Vendor sniping aside, the fact is, the move to 64-bit computing will bring us faster, more powerful machines. No matter what brand you buy, that's a good thing.