Is Itanium the first 64-bit casualty?

I remember when Windows moved from 16-bit computing to 32 bits. I had one client who kept crashing his Toshiba notebook. I’d install, and the next day the thing would be as lifeless as Michael Jackson’s bachelor party.

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He kept denying any involvement, but after the third time, I pestered him until he told me that he would only turn the machine on and “organize.” When pressed, it turned out he’d been in the Systems directory and decided to merge the two directories labeled “16-bit Applications” and “32-bit Applications” into a single “neater” directory. Eureka.

Taking the next step in bit-count without falling to pieces is always awkward no matter how much the OS manufacturer attempts to ease the pain. There are simply too many variables that must all come together. Moving to 64-bit Windows will be no exception.

A key battle for the 64-bit Windows desktop has already begun outside of Microsoft’s rain-soaked halls and inside the corporate turrets of AMD and Intel. Intel’s Itanium CPU made the first 64-bit splash but decided to completely ignore 32-bit compatibility, forcing Intel to build a WOW (Windows on Windows) system to allow customers to run 32-bit applications on an Itanium-based machine.

I’ve tried this both in the lab and in the field, and it’s never worked satisfactorily. Itanium WOW is noticeably slower than running the same application on servers using supposedly slower Pentium 4 or Xeon CPUs. Considering Microsoft’s huge delay in getting 64-bit Windows out the door, you’d think Intel might have timed the release of a 64-bit-only CPU better.

AMD made no such gamble. Both the Athlon 64 and the Opteron are 64-bit CPUs that remain based on the x86 architecture and are therefore fully backward-compatible with 32-bit applications -- meaning everything you’re running now.

What a handy feature: No slowdowns or wacky error messages when running 32-bit app code. It's so handy, in fact, that Intel announced plans to add 64-bit extensions to its own x86 CPU line, including the Pentium 4 and the Xeon series.

But if these become 64-bit compatible, what happens to Itanium? Does this line just fade away like a sandy silicon mirage? Intel’s not saying, so we’ll just have to wait and see.

Microsoft isn’t saying much either, but actions speak louder than words. Initially, it released a 64-bit version of Windows Server 2003 aimed specifically at Itanium. After AMD’s brainstorm, Microsoft announced its intent to release Windows 2003 Server with 64-bit Extensions, this one aimed at the Athlon 64, Opteron, and the soon-to-be-available 64-bit-extended Pentium 4s and Xeons. This version is still in beta, however.

Redmond also announced a similar path for Windows XP, with separate versions for Itanium and 64-bit extended CPUs, with the latter also still languishing in beta-land.

So that means Microsoft is busy releasing a mixed bag of 64-bit OS code. Linux is 64-bit ready, too, but neither camp is getting there at a breakneck pace. That means a long, convoluted transition from 32 bits to 64 bits no matter which side you’re on -- not a quick break as Itanium would seem to suggest. Frankly, someone had better announce a killer application for the Itanium soon, or that platform’s future looks about as bright as Saddam Hussein’s would be if he attended this year's Sturgis motorcycle rally.

And lest we forget, although 64-bit operating systems are arriving, 64-bit applications are still scarce and certainly nowhere near to being able to replace an entire back-end server application array. Compatibility with 32-bit software is a must for several more years, so what’s the sense in moving to Itanium when Athlon 64 and Opteron are both shipping and performing admirably in test after test running both 32-bit and 64-bit software? And these two are soon to be joined by similar x86 chips from Intel.

By the time 64-bit apps become ubiquitous, we’re looking at 2006 or later, and that’s plenty of time for some new silicon strategy to wander down the pike. Itanium may be a sexy feat of engineering, but 64-bit x86 extensions are not only the safer bet, they’re just plain more useful.