The microarchitecture, which contains technical information on the chip's subsystems, cache structure and other microarchitecture details, typically isn't publicly disclosed before the commercial launch of a chip. Hardware makers and software developers usually have copies but must sign nondisclosure agreements.
Intel, however, is shifting its policy to accommodate the changes in the industry wrought by the rise of Linux and the open-source community, said Ron Curry, director of IA-64 marketing. Open-source programming is a communal affair: Developers contribute ideas on a volunteer basis and don't necessarily work at companies covered by the nondisclosure agreements.
To ensure that a broad array of applications will be ready and debugged for Itanium's launch in the second half, therefore, Intel is releasing the documents now. In addition, the company is connecting Itanium-based servers to the Web so programmers can test-drive their software.
"If we keep everything close to the vest, it is a speed bump in the process," Curry said. "The environment has changed, with the open-source community becoming increasingly important."
Linux appears destined to play a substantial role in the acceptance of Itanium, Intel's first 64-bit processor. Itanium will process data in 64-bit chunks, twice the size that current Pentium chips handle. It will compete against processors from Sun Microsystems, IBM and Compaq Computer's Alpha division.
The chip, however, has been delayed several times. A number of analysts and computer executives have stated that Itanium will largely be a development platform. General commercial acceptance isn't expected until McKinley, the successor due in late 2001, according to many.
During these setbacks, Linux has emerged as a major vehicle for the chip. A version of Linux was one of the first operating systems to successfully run Itanium. Still, the decentralized nature of open-source programming presents a challenge.
"The community is much more fractured now, particularly the Linux community," said Mike Feibus, principal analyst at Mercury Research.
Intel is not the first company to try to win support by publishing chip designs. Last year, Sun publicly published the designs of some of its embedded processors, such as the PicoJava chip, and even loosened some of the licensing restrictions in an effort to encourage chipmakers to adopt its designs.
Many of the salient details about Itanium have already been released and are repeated in the documents posted today. As reported earlier, the chip will initially run at 800 MHz. It will contain three levels of cache. The third level of cache, which acts as a data reservoir, will contain as much as 4MB of memory.
Several companies are building servers and workstations for Itanium. Intel has also designed a two-processor workstation and a four-processor server that computer makers can adopt, said Abhi Talwalkar, general manager of the server products division at Intel.