We tested the Release Candidate 1 (RC1, Build 1289) of the 64bit version ofWindows XP Pro. As our test platform we used one AMD and one Intel system. For the AMD system, we used an Athlon 64 FX51 CPU and for the other an Intel Pentium 4 3.4GHz with EM64T 64bit extensions.

If you’re expecting the 64bit version ofWindows to look different to previous releases, you’ll be disappointed: Windows XP Pro x64 Edition looks exactly the same, has the same functions and is used in the same way as the 32bit version (see screenshot 1). Nothing has changed in the familiar interface. The important changes stay out of sight, hidden in the engine room of the operating system. Our tested version was based on the Windows XP (SP1) codebase, but nonetheless included all the features introduced in SP2, such as the Security Center, improved Bluetooth and Wlan support and the pop-up blocker.

If you look back at the major leap from the 16 bit Windows 3.11 to the 32bit Windows 95, the change to the 64bit platform doesn’t seem very drastic. WhenWindows 95 was launched, even home users were finding the 4MB Ram limit in Windows 3.11 frustrating. Today, however, even professional users ofWindows XP don’t really have memory shortage problems.

However, the advent of 64bit is by no means premature: when working on large projects in demanding areas such as video, 3D rendering or Cad, the limits of 32bit systems are already noticeable. In conjunction with the latest processors,Windows XP Pro x64 Edition supports up to 32GB of system Ram (see table 1). In addition, the amount of Ram which a single program can address is no longer limited to 2GB.

The 64bit CPU speeds up the processing of large amounts of data. It can be moved more quickly because it is moved around in larger chunks at the same clock speed. And that’s not all: according to Microsoft, when used with suitable hardware, the operating system will in future be capable of using even more Ram. If memory prices keep falling, by the end of 2007 the average amount of Ram in a PCcould be over 4GB.