Itanium is an ambitious attempt to create a chip architecture that will last for more than a decade. Hewlett-Packard initiated the project in 1988 then signed a partnership with Intel to design and manufacture the chip in an effort to spread the processor as widely as Pentium instead of seeing it consigned to the small niche many high-end processors occupy. But the Itanium family arrived years later than expected, in the midst of an industry spending freeze, and the family's first member, code-named Merced, was largely a dud. Although the second-generation Itanium solved performance problems, it didn't change the larger problem: that software has to be rebuilt to take advantage of the chip's abilities. And because the anemic 32-bit performance made it hard to run older software, Intel rivals such as AMD and Sun Microsystems were able to exploit the fact that their new chips don't force customers to deal with a "binary break" that makes older software useless. And that led Intel to consider emulation technology. "If Intel could find a way to have IA-32 code run reliably and relatively quickly on an Itanium processor, it could only help its adoption," said Illuminata analyst Gordon Haff. HP, the company with the biggest stake in the success of Itanium -- because it's moving its entire server line to the chip family -- is supportive of the move. "We're pleased with any technology that will boost the performance of Itanium-based systems for our customers. We expect this (IA-32 Execution Layer) to help customers as they migrate their applications from 32-bit to 64-bit on Windows and Linux," said Brian Cox, worldwide product line manager for HP Business Critical Systems. Intel will keep the hardware-based IA-32 support at least through the Itanium II 9M model due to arrive in 2004, Grimes said. She declined to say whether the company would rely solely on the Execution Layer software after that, but analysts believe that move is likely. Removing the hardware component would probably liberate Itanium from design compromises the chip needed to accommodate the 32-bit code, Brookwood said. And Mercury Research analyst Dean McCarron noted that "getting rid of the hardware piece of it means fewer transistors, smaller die size, and (that Itanium would be) more manufacturable." Grimes, however, said removing the hardware support wouldn't change the processor size significantly. Several factors will determine the future of the emulation layer. On one hand, Intel engineers could improve the software in succeeding generations, and its performance will increase as newer, faster Itanium models debut. On the other hand, Intel has been aggressively boosting the speeds of its 32-bit chips. One advantage of the emulation software is that it can be more easily adapted to execute IA-32 instructions that older IA-32 chips lacked. For example, the existing Itanium circuitry can't execute the SSE instructions that have been boosting some mathematical operations since the days of Pentium III, much less the SSE2 follow-on in Pentium 4 and whatever might come later. The new layer doesn't change Intel's overall Itanium strategy of encouraging computing companies to rebuild their software for Itanium, Grimes said. Customers needing top 32-bit software performance should still buy Xeon systems, she said. "Itanium is first and foremost designed to run 64-bit," Grimes said. "The 32-bit support is in there as a migration path for people as they get over to 64-bit, or for nonperformance (critical) applications they might not want to migrate."
See Chips Central for the latest headlines on processors and semiconductors.
To find out more about the computers and hardware that these chips are being used in, see ZDNet UK's Hardware News Section.
Let the Chips Central editor know what you think by email. And sign up for the weekly Chips Central newsletter.
