Depending on who you ask, Intel's 64-bit Itanium processor is either the most innovative processor ever introduced or the most colossal marketing blunder of all time—or perhaps both. The Itanium ushered in a totally new 64-bit computing architecture dubbed Explicitly Parallel Instruction Computing (EPIC). In spite of its immaturity, the Itanium and its EPIC architecture irrevocably proved its scalability in multiple benchmarks, holding the top SAP and Transaction Processing Performance CouncilTPC-C benchmarks at different times. However, the processor's ultimate downfall was that the EPIC architecture wasn't compatible with all existing x86 software. Although it offers exceptional native 64-bit performance, it could run existing 32-bit applications only by using a slow x86 emulation environment, which killed performance.

Intel's initial unwavering support of the x86-incompatible Itanium displayed an arrogance that's so often associated with big companies that control a market. Intel expected to push the market where it wanted rather than going where the market demanded.This attitude has ultimately led to the company's current market-share loss and profitability decline. Even after AMD publicly released plans for the fully x86-compatible 64-bit Opteron chip, Intel refused to budge from its Itanium-only stance until it was overwhelmingly clear that the 64-bit ship had sailed and Itanium wasn't on board. AMD Opteron's combination of full x86 compatibility plus 64-bit scalability won the day, and the Itanium has since been relegated to a niche technology.

The Windows Server 2003 Release 2 (R2) Datacenter Edition, once the stalwart Itanium OS, has completely dropped support for Itanium. There's an x64 edition of Windows 2003 Datacenter R2 but no Itanium edition. Combining Itanium's low market acceptance with both Intel's and Microsoft's recent actions, the Itanium seems to be sliding down the slippery slope of 64-bit obsolescence.To Intel's credit, when the company backed off Itanium, it jumped back into the x86 marketplace.The company revamped its product line by using 65nm dual-core technology, and—taking a lesson from AMD—increased its front-end bus capacity, simultaneously reducing its chips' power consumption.The new Core 2 Duo processor line has given Intel new life; the processor's x86-compatible 64-bit computing power has provided a platform that can successfully compete with the AMD x64 processors.

In spite of appearances, Itanium sales will continue for three reasons. First, although the mass market requires x86 compatibility, Itanium is all about high-end workloads and now targets mainframe and proprietary (i.e., expensive) UNIX implementations. This market requires Itanium's high-end power and offers much bigger profit margins. Second, Intel and Microsoft both need Itanium to compete with Sun Microsystems, IBM, and Oracle at the top of the SAP and TPC-C benchmarks. Finally, R2's new features simply weren't applicable to high-end database implementations, which is the market that currently uses Itanium the most.

Microsoft didn't make an Itanium version of Windows 2003 Datacenter R2, but that's not the same as dropping support for Itanium. Microsoft is still planning an Itanium edition of Longhorn. Although Itanium will never be mainstream technology, it's still premature to count it out. And for the upper limits of Windows platform scalability, it's still the only game in town.