x64 Adds New Dimension to Windows

Microsoft's x64 versions of Windows Server 2003 and XP Professional help 32-bit and 64-bit systems get along.

The 64-bit versions of Windows XP Professional and Windows Server 2003, when combined with systems based on Advanced Micro Devices Inc.s x86-compatible 64-bit chips (or work-alike variants from Intel Corp.), let organizations boost the performance of memory-intensive applications without giving up 32-bit cold turkey.

In eWEEK Labs tests, Windows x64 (x64 is Microsoft Corp.s name for the 64-bit AMD architecture) did a good job of juggling 32-bit and 64-bit applications running together on the same machine, which can be tricky to manage. Microsofts Internet Explorer ships with both 32-bit and 64-bit on Windows x64, and each has its own versions of various libraries that need to be kept straight.

Management can be problematic because, although AMDs architecture allows for native execution of 32-bit applications, Windows x64 (or any other 64-bit operating system weve tested) wont brook mixing 32-bit and 64-bit code. This is why code that runs in kernel mode, such as that used for hardware drivers or firewall anti-virus applications, must be ported to work with Windows x64s 64-bit kernel.

We installed Windows XP Professional x64 Edition on a Hewlett-Packard Co. xw9300 workstation with dual AMD Opteron processors and found that Windows lacked a driver for the machines on-board NIC. We tried an Intel PCI NIC next, and it worked fine.

/zimages/2/28571.gifMicrosoft says PC customers could void their warranties by upgrading to its new 64-bit Windows XP Professional OS. Click here to read more.

We couldnt locate a Windows driver for the systems on-board sound, either. The only Windows x64 drivers available on HPs Web site for the system we tested were those for the systems Nvidia Corp. graphics adapter.

On a superficial level, Microsofts two new operating system editions are essentially identical to their 32-bit siblings, but Windows x64 manages multiple-architecture complexity by maintaining separate locations for 32- and 64-bit program files and libraries and by presenting separate registry views for the different architectures, which prevents settings conflicts for applications installed in both 32-bit and 64-bit forms.

In addition, the task manager in Windows x64 shows whether the applications that are running are 32-bit or 64-bit versions .

We recommend that sites running Windows on servers powered by AMDs Opteron and AMDs Athlon 64 or Intels EM64T (Extended Memory 64 Technology)-enabled Xeon and Pentium IV—particularly with memory-intensive applications—begin testing and planning for a move to Windows x64. Provided that the proper drivers are available for your hardware, a shift to x64 on servers that support it should be a slam-dunk because the new platforms benefits can extend to 32-bit as well as 64-bit applications.

We also recommend that Windows developers get a copy of Windows x64, if they havent already done so, to begin preparing their applications—and, in particular, their drivers—for the new platform. AMD and Intel are both pushing x64, and now that Windows x64 has shipped, it wont be long until new mainstream systems are 64-bit-enabled.

/zimages/2/28571.gifMicrosofts platform rivals are already up and running with versions of their operating systems for AMDs 64-bit architecture. Click here to read more.

For desktop and workstation users, who are much less likely to be running systems with tons of RAM, the decision of whether or when to move to 64-bit Windows depends most directly on applications designed to take specific advantage of the new platform.

As with server implementations, applications with heavy memory demands, such as those for CAD or video editing, will see the greatest direct benefit.

Next page: What you get.