64-Bit Computing Allows for More RAM

In 1986, Intel introduced its first 32-bit CPU. It wasn't until 1993 that the first fully 32-bit Windows OS--Windows NT 3.1--followed, officially ending the 16-bit era. Now 64-bit processors have become the norm in desktops and notebooks, though Microsoft still won't commit to an all-64-bit Windows. But it can't live in the 32-bit world forever.

What is it? 64-bit versions of Windows have been around since Windows XP, and 64-bit CPUs have been with us even longer. In fact, virtually every computer sold today has a 64-bit processor under the hood. At some point Microsoft will have to jettison 32-bit altogether, as it did with 16-bit when it launched Windows NT, if it wants to induce consumers (and third-party hardware and software developers) to upgrade. That isn't likely with Windows 7: The upcoming OS is already being demoed in 32-bit and 64-bit versions. But limitations in 32-bit's addressing structure will eventually force

everyone's hand; it's already a problem for 32-bit Vista users, who have found that the OS won't access more than about 3GB of RAM because it simply doesn't have the bits to access additional memory.

When is it coming? Expect to see the shift toward 64-bit accelerate with Windows 7; Microsoft will likely switch over to 64-bit exclusively with Windows 8. That'll be 2013 at the earliest. Meanwhile, Mac OS X Leopard is already 64-bit, and some hardware manufacturers are currently trying to transition customers to 64-bit versions of Windows (Samsung says it will push its entire PC line to 64-bit in early 2009). And what about 128-bit computing, which would represent the next big jump? Let's tackle one sea change at a time--and prepare for that move around 2025.