All the major Unix vendors are on track to deliver IA-64 versions of their operating systems by the time Intel starts shipping its Merced chip next year.
But users may have to wait for the arrival of Merced's successor - McKinley, scheduled for 2001 - before they get many applications that take full advantage of IA-64 servers.
That's because it will take at least that long for many of the compilers, debuggers and software tools needed to optimise applications for IA-64 to become available, analysts said.
"In many cases, users are just going to wait for packaged applications to become available on IA-64 before moving to it," said Jonathan Eunice, an analyst at Illuminata.
IA-64 is the 64-bit chip architecture that Intel and Hewlett-Packard have been jointly working on since 1994. Unlike current-generation complex instruction set computing and RISC-based systems, IA-64 uses a technology called explicitly parallel instruction computing.
The technology promises to let users run Windows NT and Unix applications equally well - and at a lower cost than current RISC-based servers.
Currently, Unix development efforts relating to IA-64 have consolidated around three major camps - one led by IBM, one by HP and a third by Sun Microsystems. Their efforts so far include the following:
-- IBM is spearheading a multivendor effort to build a version of Unix code-named Monterey for IA-64. Monterey combines elements of IBM's AIX operating system with Sequent's Dynix PTX and The Santa Cruz Operation's (SCO) UnixWare. The merged Unix will include technologies like Sequent's Non-Uniform Memory Access and multipath I/O as well as SCO technologies like Universal Device Interface. IBM has said it will offer Monterey on its servers.
-- HP's HP-UX 11, which began shipping in 1997, is a 64-bit, IA-64-ready, mission-critical operating environment. According to HP, HP-UX customers will enjoy full IA-64 binary compatibility without changing or porting their applications. Dynamic Object Code Translation technology, a very high-level form of emulation, allows users to run a mix of binaries on their systems.
-- Compaq will have a development version of its Tru64 Unix for Merced when Intel announces the chip. The operating system won't be ready for deployment in production environments until McKinley arrives, Compaq said.
-- In March, Sun, like the other vendors, demonstrated a version of Solaris running on a Merced simulator. The company is preparing to release a beta version of Solaris 8 along with the latest Merced simulator to key software vendors.
Several of the performance-boosting features of IA-64 can be harnessed only by code designed for the architecture, analysts said.
The options that users have for moving their existing applications to these environments depend on their current Unix version. Most users of UnixWare, for instance, will be able to run current applications on IA-64 either by doing a 32-bit recompilation on IA-64 (without touching the source code) or by running them in a sort of emulation mode, said Mike Foster, a marketing director at California-based SCO.
Users of IBM's 64-bit AIX, meanwhile, will have a source-level compatibility with IA-64 and should be able to get most performance benefits by recompiling existing applications on IA-64, said Miles Barel, an IBM program director.
HP-UX will run both PA-32 and PA-64 applications unchanged, along with IA-64 native applications, using its Dynamic Object Code Translation technology.
"For most users, it's going to be a bit of a hassle but not a major disruption" to move current applications to IA-64 servers, Eunice said.