Xp goes to 64 bits

The slow but inexorable march to 64-bit computing--the successor to familiar 32-bit x86-based technology, which has dominated the desktop world since the advent of Windows 95 almost a full decade ago--seems poised to speed up. Not only has Microsoft announced its plans to release its first 64-bit operating system for mainstream desktops, Windows XP Professional X64 Edition, by the middle of this year, but also the company has delivered its initial Release Candidate (RC1) of the operating system. Microsoft has produced 64-bit OSs before, most recently Windows XP 64-Bit Edition for high-end workstations powered by Intel's Itanium CPU, but XP X64 is the first Windows OS designed for PCs based on 64-bit CPUs that can also run today's 32-bit apps--most notably AMD's 64-bit Athlons, which have been on the market since 2003. Only with a 64-bit OS and applications can early adopters enjoy everything 64-bit computing has to offer, including access to up to 16 terabytes of RAM. (RC1 supports only 32GB of RAM--Microsoft says that the shipping OS will support 128GB--as well as 16 terabytes of virtual memory, but that's still vastly greater than the 4GB maximum of today's 32-bit systems.) For users, that translates into greater speed: 64-bit apps won't have to swap large data sets between memory and disk, and will therefore be able to load and process the data faster and more efficiently than 32-bit programs can. In use, XP X64 feels quite similar to 32-bit versions of Windows--with a few noteworthy exceptions. The Start menu, for example, has two renditions of Internet Explorer: a new 64-bit version and the same 32-bit version that Microsoft shipped in XP SP2. Why? Since 32-bit plug-ins for IE won't run in the 64-bit version, Microsoft had to retain the 32-bit version for people who want to keep using legacy IE add-ons, such as QuickTime or Google Toolbar. Because many 32-bit applications continue to use 16-bit installers, they can't be installed on XP X64. Of course, the biggest benefits of 64-bit computing can be realized only when applications capable of taking advantage of its huge memory resources appear. Several companies have offered vague promises about developing native 64-bit programs, but concrete plans are rarely available. NewTek says it will port its Emmy Award-winning LightWave 3D graphics and visual effects package to X64 sometime this year. Epic Games has pledged to release a 64-bit version of its Unreal Tournament 2004, but this has not yet materialized. The crucial factor is mainstream application support from Microsoft, Adobe, and other top-tier vendors--and they're not talking on the record. Hardware device drivers are another problem. Today's 32-bit drivers won't install on XP X64; and even though RC1 includes a wide range of drivers for popular devices, the absence of third-party drivers will torment many users of the new OS. (Owners of 64-bit PCs can download RC1 from Microsoft's Web site.)