Microsoft Corp.s launch of x64 editions of Windows Server 2003 and Windows XP is particularly significant for the spread of 64-bit computing because these releases mark the meeting of the worlds most ubiquitous operating system with the first 64-bit architecture with legs enough (thanks to its capacity for natively running x86 code) to win broad marketplace acceptance.
However, while the massive volume of Windows sites immediately pushes Microsoft to the front of the 64-bit operating system field, the companys platform rivals have, for some time now, been up and running with versions of their operating systems for Advanced Micro Devices Inc.s 64-bit architecture.
When Opteron processors began shipping a little more than two years ago, eWEEK Labs tested the new Opterons with SuSE Linux AGs SuSE Linux Enterprise Server 8 for AMD64. Today, Novell Inc. markets versions of its SuSE Enterprise, SuSE Professional and Novell Linux Desktop products for AMD64.
Novell isnt alone in its support for AMDs 64-bit platform: Commercial Linux distributors Red Hat Inc. and Mandriva S.A. (formerly Mandrakesoft S.A.) also support the platform across their product lines, and the popular noncommercial Linux distribution projects Debian, Gentoo and Fedora Core each maintain AMD64 versions as well. Whats more, NetBSD, OpenBSD, FreeBSD and Solaris 10 are all available in a 64-bit version for the AMD64 architecture.
The 64-bit Linux distributions weve tested handle the running of 32-bit and 64-bit applications together on the same system in much the same way that Windows does: These distributions offer compatibility libraries for running 32-bit applications, and they store incompatible binaries in separate locations to keep things straight.
Weve also had success running 32-bit applications on a 64-bit Linux system using the Linux application chroot, which provides a separate environment for the application to run with.
As with Windows x64, AMD64 versions of Linux require particular drivers, and weve experienced assorted troubles with software availability—particularly with proprietary software such as Macromedia Inc.s Flash player and Adobe Systems Inc.s Acrobat Reader plug-ins, both of which must be used with a 32-bit version of ones chosen Web browser.
Linux on AMD64 enjoys the advantages of a head start; for instance, the Hewlett-Packard Co. workstation on which we tested Windows XP x64 has more drivers available for Red Hat Enterprise Linux 4 for AMD64 than for Windows x64.
Apple Computer Inc.s Mac OS X doesnt run on AMD64, but the PowerPC G5 processor that drives Apples latest systems is a 64-bit chip with backward compatibility for earlier 32-bit PowerPC code.
Apples newly released OS X Tiger isnt a 64-bit operating system—nearly all of its code remains 32-bit—but Apple has leveraged the architecture enough to extend the memory limitations of previous Mac OS releases, and it has provided for a set of 64-bit math libraries for applications to call on.