Microsoft"s march towards 64-bit glory

25.03.2005
Von Louis Chua

The relentless march toward 64-bit computing will take an important step forward this year with the launch of Microsoft Corp."s Windows Server 2003 64-bit edition and Windows XP 64-bit edition.

This is the start of a new upgrade cycle, similar to the previous cycle of upgrade from 16-bit to 32-bit, said John Borozan, senior product manager, Windows Server Business Group, Microsoft. He believes that in 2005, most of the new Windows-based server shipments will combine x64 hardware with 32-bit Windows. With the x64 release of Windows, customers will start combining 32-bit and 64-bit applications on the same system.

In fact, he said, almost 60 percent to 70 percent of server hardware shipments are based on 64-bit hardware running 32-bit Windows, only that the customers are unaware of it.

Over time, said Borozan, customers will increasingly use pure 64-bit software based on x64 hardware. And this will take a while -- even though the extended 64-bit architecture can do more ? as we already have sizable investment in 32-bit software and skill sets. The migration will not just involve Windows server and Windows -client but the associated device drivers and applications as well.

On the server end, Microsoft sees early adopters in areas where memory constraints are most apparent, such as in the database, terminal service and business applications. In the x64 architecture, applications will have 4G bytes of address space. On the client side, Microsoft promises stronger security settings for the new Windows XP Professional x64 edition. The Windows XP x64 edition is built on top of Windows Server 2003 code base and includes the Windows XP SP2 enhancements as well.

One of the features is Windows XP x64 will prevent applications from patching the kernel. Microsoft is also working closely with the antivirus vendors to provide compatibility.

"In my opinion, we have squeezed as much performance as we could out of 32-bit," said Brad Waters, development manager, Microsoft. He believes that a large number of application code manage constrained memory by jumping through limitation hoops to avoid the 32-bit memory limits.

On x64 systems, not only is there more accessible memory, there are also a lot more new registers available for developers and vendors to use instead of restricting the number of registers they can access.