Software architecture was the key strategy by AMD.  Instead of following in the footsteps of Intel, AMD decided they would retain the ability of their "eighth generation chip" to run 32bit applications.  For those that don't need 64bit it changes nothing. That single important decision (we believe it a wise one), has set the stage for the Opteron to be a much bigger success than the Itanium. 

Who needs 64bit addressing and 64-bit calculations? Most of the hosting applications are not in dire need of 64bit processing but we have set the stage by building servers that will be able to utilize the new Microsoft 64bit OS when it becomes available.   Sixty-four-bit systems process more data per clock cycle, allow access to more memory and speed up numeric calculations.

Microsoft has worked with AMD to develop 64-bit operating systems for its Athlon and Opteron chips.  Athlon is meant for use in desktop computers and Opteron for workstation and server systems; 64-bit operating systems have been available on the competing Unix platform for years.

At the time I write this you can receive trial software for Windows XP 64-Bit Edition via CD or download.  Most employees of SecureWebs are running at least the Athlon64 processor so that we can explore this as time provides.  FreeBSD, and others already have a 64bit offering.

The critical decision for the Opteron to run 32-bit legacy code far faster than even the Itanium could ever hope to is surely going to be the downfall of the Itanium. It would not surprise this writer if history judges the Itanium to be a staggering mistake for HP and Intel and allows AMD entry into the high-end server market they covet.