The 64-Bit Question

When computers improved from 16 bits to 32, they became vastly more powerful and useful. But the advance to 64 bits may prove beneficial more to computer marketers than to users.

By Simson Garfinkel

June 2, 2004

Is a 64-bit computer in your future?

With all of the hype surrounding 64-bit processors, you probably assume that my answer would be an unequivocal "yes-and pretty darn soon, too!" But put aside the marketing bluster about chips like AMD's Athlon64; in fact, having 64 bits matters a whole lot less than the computer industry would have you think. Indeed, unless you happen to be a Macintosh user, you might not find yourself buying a 64-bit computer for another decade-if, in fact, you ever buy one at all.

First, a little background. The processors in the vast majority of today's desktop and laptop computers are 32-bit chips. Most of them, are based on Intel's incredibly successful IA32 architecture, also known as the x86 (as in 286, 386, 486). Intel's Celeron and Pentium machines are all IA32, as are AMD's Athlon chips. 

But all of a sudden, 64-bit machines have a kind of cachet. For two years, AMD has been selling processors that can run both 32-bit and 64-bit code at the same time; computers built with these chips can run either Linux or a special 64-bit version of Windows XP that Microsoft released earlier this year. Apple, meanwhile, ships all of its Power Mac computers with the G5 microprocessor, a 64-bit brain created by IBM. And in a way, all of these desktop systems are playing catch-up: Nintendo made the 64-bit transition in 1996 when it shipped its Nintendo64 gaming console.

Story continues below

To understand why all this matters, you first need to understand that the phrase "32 bits" is a kind of shorthand that computer designers use. This number refers to two things inside the computer's architecture. First, it signifies how many bits these computers use when they specify the location in memory where a piece of information is stored. Second, it indicates the size of the registers inside the microprocessor that are used to do math. Each bit can be a 1 or a 0, so 32 bits can be used to represent 2³² or 4,294,967,296 different values. Thus, the obvious difference between 32-bit machines and 64-bit ones is that the 64-bit systems are much bigger machines: they can address more memory, and they have can do math with bigger numbers.

But more doesn't necessarily mean better-it depends on what you are getting more of.