Last November at the Microsoft IT Forum 2005, Microsoft announced its plan to migrate its server products from the 32-bit x86 platform to the new 64-bit x64 platform in 2006—a controversial topic among its enterprise customers. During the transition period, some Microsoft products will operate only on the x64 platform (effectively orphaning many of today's 32-bit servers), whereas other products will run on both the 32- and 64-bit versions for the short term to allow customers time to migrate to the 64-bit technology. Confused? Here's what you need to know about Microsoft's x64 server product plans.

The Justification
I began speaking with Microsoft representatives about the transition to the x64 platform a few years ago. In 2005 they told me the transition was well underway. "Today, x64 hardware is virtually all you can buy anyway," Samm DiStasio, a group product manager in Microsoft's Windows Server team, recently told me. "But many of our customers don't even realize that they've been buying x64 hardware."

At issue here is the almost viral-like way in which x64 hardware has propagated throughout both the server and desktop worlds. The x64 platform—initially developed by AMD and known as AMD64—is designed to be fully backward-compatible with today's 32-bit (x86) microprocessors yet provides the benefits from the 64-bit processors, such as 64-bit memory architecture that expands system memory and helps 32-bit applications achieve better performance. The AMD64 platform was so successful at providing a technical best for both 32- and 64-bit platforms that other manufacturers have followed suit.

Microsoft's 64-bit platform has security improvements such as Data Execution Prevention (DEP) technology, which provides better protection against an intruder who attempts to run malicious code on Windows client and server products. "We put something called patch guard into the kernel in "x64" so that it is not possible to install a patch in a running kernel, which is possible in "32-bit" when you have administrative privilege," Microsoft's Senior Vice President Bob Muglia said recently. "In 64-bit, we stopped that."

The catch-22 situation for the x64 platform is the slow development of 64-bit drivers and software applications. Most PC and server manufacturers are currently selling their computer systems with 32-bit OSs and applications. As a result, sales of native 64-bit software (e.g., Windows XP Professional x64 Edition on the client) have languished, device manufacturers are slowly delivering 64-bit drivers, and software applications are still being designed with 32-bit code. It's ironic that most users who have x64 PCs and servers don't take full advantage of 64-bit capabilities.

Although Microsoft recognizes that it will take time for users to move to the x64 platform, the company has researched the marketplace and determined that the logical place to lead the x64 revolution is in the server market. This makes sense for a few reasons:

  • 64-bit drivers are hard to come by right now
  • server configuration scenarios are less varied than desktop configurations and as such are more likely to be included in the Windows Hardware Compatibility List (HCL)
  • there are fewer applications running on a server
  • servers can best take advantage of the native scalability and performance advantages of the 64-bit architecture.

Today, Microsoft ships an x64 version of most Windows Server 2003 products, and recently shipped SQL Server 2005 in 32- and 64-bit versions. Going forward, Microsoft will be more aggressive at phasing in x64 and phasing out x86 products.

Microsoft's Transitional Products
As you might expect, Microsoft will begin the transition process by selecting products (such as server products) that will show the most improvement when running on the x64 platform. For example, Longhorn Server (due in 2007) will initially support 32- and 64-bit applications, but Longhorn Server R2 (due in 2009) will be available only for the x64 platform. Microsoft was careful to note that this transition doesn't mean it will abandon 32-bit Windows Server customers. "Remember that we will be supporting the 32-bit versions of Longhorn Server until 2012, and extended support will be available through 2017," DiStasio told me. "Customers will have the option to continue with 32-bit." DiStasio also noted that Microsoft will provide service packs for both the 32-bit and 64-bit versions of Longhorn Server.

Other products, such as SQL Server and Virtual Server, will be available in both 32-bit and 64-bit versions through the current product generation, but Microsoft is still evaluating how and when it will begin dropping 32-bit products. Plans for other 32-bit server products today are unknown. Remember, 64-bit versions of Windows Server 2003 and later can run 32-bit server software natively without any performance problems or compatibility concerns, meaning 32-bit software will be around long after the x86 hardware disappears.

x64-Only Products
Some eagerly awaited Microsoft products will ship only in x64 versions. Windows Compute Cluster Server (CCS) 2003, scheduled to ship in the first half of 2006, is Microsoft's first attempt at breaking into—and expanding—the supercomputing market. Windows CCS is based on Windows Server 2003 x64 with Service Pack 1 (SP1) and includes simplified cluster setup and management, image-based node management, and Active Directory (AD) integration, and seeks to (in Microsoft's words) bring high performance mainstream. Windows CCS is based on the x64 platform for obvious reasons: It will take full advantage of the performance and scalability inherent in the flat 64-bit memory architecture.

It may seem obvious that Microsoft's supercomputing platform would be based on the x64 platform, but some of the company's other x64 products may surprise you. In late 2006, Microsoft will ship the next major version of Exchange Server, code-named Exchange 12, as a 64-bit-only product (see "Exchange 12: The 64-bit Question," page 51, InstantDoc ID 48915. Other upcoming x64-only products include Windows Server "Longhorn" Small Business Server (SBS), and the new medium-business server, code-named Centro.

What About Itanium?
What's still up in the air, is Itanium support. Intel's high-scalability microprocessor solution has established only a niche market, although both Intel and Microsoft continue to staunchly support the product. However, Microsoft's Itanium-based product line is somewhat lackluster. "Microsoft continues to license and support Windows Server 2003 Enterprise and Datacenter editions for Itanium-based systems, and the 64-bit version of SQL Server 2000 Enterprise Edition," Muglia said. Microsoft continues to support Visual Studio 2005, .NET Framework 2005, and SQL Server 2005 on the Itanium platform.

Recently, Microsoft decided to limit the Itanium version of Longhorn Server so that it addresses just three core workloads: high-end databases, line of business (LOB) applications, and custom applications. The company has been careful to couch this decision in a positive light, noting these three workloads are really the only tasks customers use on the Itanium platform today. So is Microsoft planning to walk away from the Itanium market? "Think about it this way," Zane Adam, the director of marketing for the Windows Server Division at Microsoft told me, "Longhorn Server starts a new support life cycle for us. Enterprises are going to use it for several years, well into the next decade."

One might argue that the Itanium markets aren't niche markets, but are rather core to the company's goal of migrating enterprise customers from proprietary UNIX solutions to Windows Server. But as the x64 platform scales up, it will inevitably bump into the seemingly moribund Itanium, unless Intel is able to magically jumpstart Itanium development and adoption. Plus, one needs only to look at Microsoft's support of MIPS, PowerPC, and the Alpha—all three processors were superior to the x86 platforms of the day—to find evidence to suggest the company will abandon Itanium when it can. Today, Itanium is a safe bet for the highest-end applications and services. Tomorrow isn't so certain.

What About the Desktop?
Another curious omission from Microsoft's x64 roadmap; how it will move desktop systems to the 64-bit solution. To date, Microsoft has said it expects x64 to be the mainstream platform by the time Windows Vista is available in late 2006. Most Windows Vista editions will initially be available in both 32- and 64-bit versions, but it's unclear whether Microsoft will sell these products separately or create integrated installers that optionally install either x86 or x64 binaries.

Concerns about x64 on the desktop, are legion. Until 64-bit drivers are available for the millions of hardware devices that already exist, customers will be unwilling or unable to switch to a 64-bit version of Windows XP or Windows Vista. Why? First, some applications still inexplicably use older 16-bit installers, and x64 versions of Windows will not run 16-bit code. Second, some 32-bit applications are designed to access core parts of the system, such as the kernel, which are off limits in 64-bit Windows versions, including some antivirus and antimalware solutions. Finally, applications that extend the Windows shell (e.g., file archiving) or plug into Internet Explorer (IE) don't run on Windows x64 because the system's shell components have been rearchitected in 64-bits. These types of applications will have to be rewritten to run natively on the x64 platform.

Curiously, Microsoft doesn't adequately support the x64 platform with its own applications. Although Microsoft Office runs fine on Windows XP x64, some applications, such as Windows Desktop Search, work only with 32-bit versions of Windows. The company has pledged to resolve those issues.

My expectation is that the desktop will move to the x64 platform slower than server products will. The hardware and software compatibility issues are just too great to overcome for mainstream users to feel comfortable with 64-bit versions of Windows in the year ahead.

Recommendations
Although Microsoft's seemingly aggressive migration to the x64 platform may seem shocking at first, I think they're doing the right thing. The server market is already awash in x64-compatible Xeon- and Opteron-based servers. By providing its customers with a clear roadmap now, Microsoft is taking the guesswork out of your planning. From a technical standpoint, x64 is clearly the way to go. Now, all we need to know is how Microsoft intends to take its desktop platforms to x64 as well.