Microsoft Readies 64-Bit WindowsMicrosoft Readies 64-Bit Windows

It's safe to say that Robert Pennington is happy with Intel's new 64-bit Itanium processor. As associate director of computing and communications at the National Center for Supercomputing Applications, he's responsible for all the production supercomputing systems, including several new Itanium clusters. "We've been able to port 32-bit Windows applications to Itanium by recompiling them, and the performance is outstanding," Pennington says.

On one particular system that relies heavily on the Itanium's number-crunching capabilities, a molecular dynamics modeling application called Gamess, performance was leading-edge. "We had a visiting scientist spend two weeks tuning it for Windows on Itanium," Pennington says. "When we ran it on a cluster of four machines, each with two Itanium CPUs and a fast Ethernet interconnect, the aggregate performance was over 12 gigaflops-1.5 gigaflops per processor-the fastest performance that had been seen anywhere on a per-CPU basis for that application."

Still, when Pennington brings the Itanium clusters online, where they'll become one of the main computing systems serving the national scientific community, they'll be running 64-bit Linux, not 64-bit Windows. "The interest on the part of the users is mostly in Linux clusters," Pennington says. "That's because their applications all run under 64-bit Unix right now, and the transition from Unix to Linux is much easier."

Application support is the reason often cited for deploying Windows, instead of competing operating systems, on the desktop. But in the world of 64-bit big-iron servers, where Unix vendors such as Compaq, Hewlett-Packard, IBM, Silicon Graphics, and Sun Microsystems have ruled for some time, Microsoft is the newcomer.

With the introduction of 64-bit versions of its Windows operating system for workstations and servers, Microsoft will be competing with these Unix vendors, as well as with Linux newcomers, for the high-end 64-bit computing market-a crowded but lucrative market, analysts say. "The volumes are really small, but the revenue is incredibly large due to the size of the systems and the related database products," says Rob Enderle, a Giga Information Group research fellow.

For the scientific, data warehousing, business-intelligence, and Web-serving markets that are the most common customers for 64-bit systems, Windows will now become another platform choice.

For IT departments, the Windows and Itanium combination has potential advantages over other vendors' products. Systems running 64-bit Windows will co-exist more compatibly with servers running 32-bit Windows as well as with desktop users of 32-bit Windows machines. There's also the potential for a larger choice of applications available under 64-bit Windows as 32-bit Windows applications are ported.

The Linux community will be a major competitive force facing Windows on Itanium servers as applications are ported to 64-bit Linux. Also, Linux vendors say they're in a better position to compete with Microsoft on Itanium than they were on the x86 chips.

"Historically, Linux has always played catch-up-Microsoft always got the nondisclosure agreements first and early access to information," says Michael Tiemann, open-source vendor Red Hat Inc.'s chief technology officer. "With Itanium, this is the first time that Linux has a fair start. When the gun went off, we were both at the starting line. If Linux is gaining market share against Windows in an unfair race, it will be interesting to see what's possible in a fair race."

Microsoft is also going after the 64-bit desktop market-the scientific, financial, and engineering workstations that can benefit from the 64-bit Itanium processor. With 32-bit business desktop dominance a given, Microsoft's 64-bit workstation operating system may prove especially attractive to companies that have long had to support one platform for their engineers and another for the rest of the company. "It's been too long that the engineering department has had their thing and the business side of the company had another," says Michael Reger, deputy director of the products and system integration group for Unigraphics Solutions Inc. "Engineers don't just sit around doing mechanical CAD all the time. They also need other applications."

This isn't the first time Microsoft has entered a server market on multiple platforms. In 1993, Windows NT 3.1 was released on three different architectures: Alpha, Mips, and Intel. Now, Microsoft is splitting its mainstream Windows operating system line into two architectures: Intel's x86 and IA-64. Microsoft will sell 32-bit versions of Windows for workstations and servers running on x86 CPUs and 64-bit versions of Windows for workstations and servers running on IA-64 processors such as Itanium.

The new 32-bit versions of Windows will run on x86-compatible processors just as before; they will run existing 32-bit applications and even 16-bit DOS applications. But the IA-64 processor line, of which the Itanium is the first CPU on the market, has a different architecture than the 32-bit x86 processors on which Microsoft has based its core Windows releases for many years.

Intel's Itanium chip includes binary compatibility in hardware for the IA-32 instruction set, but it runs legacy 32-bit x86 apps more slowly than they would run on equivalent 32-bit hardware. "They run significantly slower, which is why we don't recommend using it," says Jason Waxman, Itanium product marketing manager at Intel.

On the 64-bit versions of Microsoft's Windows operating system, legacy 32-bit Windows applications run on a compatibility layer called WOW64 (Windows on Windows 64), which uses the Itanium's IA-32 binary compatibility mode to run applications. WOW64 is necessary because many 32-bit apps may never make it into 64-bit versions.

Desktop business applications, for example, don't normally need 64-bit bandwidth. Microsoft Office is under evaluation for porting to Itanium, according to Microsoft, but its appearance in 64-bit form is uncertain. However, Visual Studio and Internet Explorer 6 will be available in 64-bit versions.

The 64-bit versions of Windows Server will come with 64-bit Internet Information Server, Active Directory, Kerberos, and other bundled server applications. But a 64-bit version of SQL Server-considered a critical app for 64-bit systems-isn't expected to ship until two months after the 64-bit version of the Windows Server, which puts its availability in the first quarter of next year.

For applications to take advantage of 64-bit performance and scalability, they will have to be ported, a process that can be tedious and costly. With Linux, many applications are available in source form, so the Linux community can get involved in the porting process. Windows applications typically aren't available in source form, meaning that the vendors are responsible for porting and supporting 64-bit versions of their applications.

For Unigraphics, whose CAD/CAM product comprises 14 million lines of code and runs on many different platforms, moving to 64-bit was a decision made early on. First ported to the 64-bit Alpha CPU running on OSF/1 back in 1995, the port took six months to complete because much of the code assumed that "pointers and long integers were 32-bits," Reger says. A major stumbling block for porting 32-bit applications to 64-bit processors is correcting code written by programmers who mistakenly assume that data types will always have a certain bit length.

But Unigraphics' early porting experience has given it a well-structured code base from which to port. Subsequent ports to 64-bit platforms have been far easier. When it came time to port Unigraphics to Windows running on Itanium, "some code broke, but just a little," Reger says. "Porting to Itanium required less than a month because almost all the code wasn't assuming 32-bit anything."

Still, Reger is eagerly awaiting 64-bit versions of Microsoft Visual Studio and compilers so that his programmers can develop and test directly on Itanium systems. For now, Windows programmers targeting Itanium systems must develop on 32-bit Windows systems using cross-compilers and then move binaries over to Itanium systems for testing.

For business-intelligence software maker SAS Institute Inc., porting to multiple 64-bit platforms is a way of life. Having recently rolled out 64-bit versions of SAS for AIX, HP-UX, and Solaris, the actual porting to Itanium wasn't a major concern despite an application comprised of 25 million lines of code. "The problem isn't in the porting, it's in the productization, quality assurance, and support," says Kevin Payne, SAS's director of Microsoft partner programs.

Microsoft's engineers agree that actually porting the code isn't the biggest problem. "While the initial porting is fairly easy, the testing isn't," says Clyde Rodriguez, Microsoft's lead project manager for Windows 64-bit development. Itanium workstations running SAS have the potential to level the performance playing field. "Really complicated business intelligence used to be reserved for the elite because you couldn't run it on a conventional PC," Payne says.

Device drivers are another area where vendors will have to concentrate resources. Though Microsoft says that its 64-bit Windows systems will ship with 4,000 devices supported out of the box, existing 32-bit device drivers won't work on 64-bit Windows systems and will need to be ported. They also will have to conform to the plug-and-play specification. The lack of 32-bit device-driver support also may affect some 32-bit applications running on WOW64 that assume the existence of certain drivers. Both 64-bit and 32-bit Windows operating systems will share the same source-code base, which theoretically means that Microsoft will be able to ship 32-bit and 64-bit operating systems at the same time. But not all features of 32-bit Windows will be in 64-bit Windows.

For one, the versions of 64-bit Windows will be the first workstation or server operating systems Microsoft has shipped without MS-DOS support. Opening a command line window will provide a shell environment, but it has nothing to do with MS-DOS and won't run MS-DOS applications.

Windows Product Activation, a new feature in 32-bit versions of Windows XP and Windows Advanced Server designed to help reduce piracy, is also missing from 64-bit Windows. Windows Product Activation, which registers newly installed systems with Microsoft to verify that per-seat licensing restrictions are adhered to, targets the casual user who might attempt to share software CDs with others. "It wasn't ported because we don't have the same piracy concerns as we do with the 32-bit version of Windows," Rodriguez says.

When Windows XP and Advanced Server ship, don't expect to find the 64-bit versions in your local computer store. Both the 64-bit workstation and server versions will be available only through manufacturers such as Compaq, Dell, Fujitsu, HP, and Hitachi, which will ship it pre-installed in their Itanium-based workstations and servers. Customers and developers who want just the operating-system binaries will have to get them via subscriptions from the Microsoft Developer Network or Microsoft's Technet Plus.

Customers interested in running other 64-bit operating systems alongside Windows will find that they coexist more peacefully than on 32-bit systems. That's because Intel has added a hardware feature to Itanium systems called Extensible Firmware Interface, an interface between the operating system and the low-level booting and initialization firmware of the computer. "EFI sets a standard that never existed in the world of IA-32. That absence made it difficult for Windows and Linux to co-habitate," Tiemann says. "EFI makes the dual booting process more maintainable."

Though more than 30 vendors are shipping Itanium systems this year, some 64-bit software apps are so computation-intensive that even Itanium may not be powerful enough compared with other available systems. Unigraphics' Reger is looking to McKinley, the follow-on chip to Itanium, for the kind of price and performance his applications demand. McKinley, which will have better integer and floating-point performance, as well as higher clock rates, will be released next year.

Windows on Itanium is competing with other chips, including the next-generation x86-64 architecture from Advanced Micro Devices Inc. and 64-bit Linux. Microsoft's 64-bit Windows also faces an entrenched field of Unix vendors with far more experience selling and maintaining high-end systems. Though Microsoft's desktop supremacy could buy it seats in this market, the number and quality of 64-bit Windows applications may be what ultimately brings customers into the fold.