Differences between the architecture of Intel's Itanium (Merced) and its future McKinley design mean that moving from one to the other is unlikely to prove a piece of cake. Sources said that McKinley will differ so radically from the Itanium that Intel is pushing further resources into Itanium to transform it from the development platform everyone was talking about last year to a real, live kicking platform. McKinley, which is expected to use .13µ technology and Intel copper interconnect technology, is not expected to surface until 18 months after Itaniums become available on the market. Most realistic estimates for when Itanium boxes become marketable are citing September or October this year. The 64-bit McKinley architecture is expected to iron out some architectural glitches which appeared at an early stage in the design of the Merced microprocessor. According to engineers, McKinley's bus structure differs from the Itanium, and Intel will provide additional transistor functionality as well as the copper technology to give far better performance than the first IA-64 chip will do. That increased performance is likely to compensate for difficulties with the IA-64 compiler. Additional work will be needed for system designs, compilers, tools and operating system support, although it is likely that at the application level things will pan out. All in all, that could mean the move from Itanium to McKinley, when it happens, may not be as smooth as current Intel roadmaps are suggesting. ®