64-Bit CPUs: What You Need to Know - Page 18

IA-64 is an interesting architecture that borrows from and/or extends many existing microarchitectural techniques, and also adds some new and interesting twists, but the first instantiation of the architecture, Itanium, has not been a major success to date. After waiting a few years longer than originally anticipated for the first IA-64 chip to appear (Intel publicly disclosed initial IA-64 details at Microprocessor Forum in 1997, and stated the first IA-64 chip, code-named Merced, was expected to ship in mid-1999), we saw a processor with a slower than expected clock rate, and less than stellar integer performance that catered to a very limited market. Plus initial shipments were stymied with delays from key vendors. Some commentators called Intels first IA-64 chip "Unobtanium". And not surprisingly, the catch-phase for quite some time has been "wait for McKinley, Itanium is simply a development platform".

Very recently another setback occurred with Dell dropping Itanium workstations from its product lineup (see "Dell Discontinues Itanium Workstation"), possibly encouraging even more people to "wait for McKinley". But clearly Itanium is not all that bad. Floating-point performance as seen in some benchmarks is impressive today, and its large address space can certainly be useful in various high-end applications, but Intel faces a steep uphill battle trying to convince many server and workstation customers, with long histories using established 64-bit architectures, to convert to IA-64 at this juncture. Then again, Intel has swayed many customers to convert portions of their application processing to Itanium-based solutions as seen at this link. Software developers are a key target as well, and many have been on the IA-64 bandwagon for a while.

Things could improve substantially when McKinley arrives later this year in development systems and early next year in volume. We expect Intel to start seriously ramping IA-64 architecture processor shipments in selected markets within two three years. But lets not forget about AMD, who clearly appears to up for the challenge, as well see in our next segment. Also, well provide our thoughts on the rumored Yamhill 64-bit x86 "hedge your bet" technology under deep wraps within Intel development labs.


  • Itanium manuals. Be sure to explore the menu to the left of the page - it has links to lots of other Itanium reference material including some PowerPoint slides.
  • A nice quick overview of basic Itanium features can be found here.
  • A set of performance tests and a summary of SPEC test results are at this link from last summer.
  • Intels own benchmarketing results are at this link.