Intel Itanium Architecture Abandoned After 18-Year Failure to Replace x86
What happened
Intel's Itanium architecture, developed with HP and launched in 2001 as the successor to x86, never achieved mainstream adoption. The VLIW architecture placed instruction scheduling responsibility on compilers rather than the CPU, but compilers could not match the performance gains x86 achieved through hardware scheduling. The last Itanium CPUs shipped in 2021 after two decades of gradual irrelevance.[1]
What went wrong
The EPIC/VLIW architecture assumed compiler technology would advance faster than it did. Meanwhile, x86 chips improved hardware out-of-order execution more rapidly than expected. Itanium's lack of binary compatibility with the vast x86 software base meant the performance gap had to be enormous to justify adoption — a gap that never materialised.[1]
Lesson learned
Betting an entire architecture on assumptions about external technology trajectories (compiler improvement) is high risk. Binary compatibility is an enormously powerful moat — the software library built on x86 proved impossible to abandon even when a potentially superior architecture was available.
Sources
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