A shocking revelation has emerged from Intel's past that could have changed the entire course of computing history. Bob Colwell, the chief architect behind Intel's Pentium Pro through Pentium 4 processors, recently disclosed that Intel actually developed its own 64-bit extension to x86 architecture years before AMD's groundbreaking AMD64 hit the market in 2003.
Key Timeline:
- 2000: AMD publishes x86-64 ISA specifications
- 2001: Intel releases first Itanium processor
- 2003: AMD launches Athlon 64 with x86-64 support
- 2004: Intel introduces EM64T (later Intel64) cloning AMD's approach
- 2020: Intel discontinues Itanium after years of declining relevance
Intel's Hidden 64-bit Technology
The Pentium 4 processors contained fully functional 64-bit capabilities that were deliberately disabled or fused off by Intel management. This wasn't a technical limitation but a strategic business decision driven by fear that x86-64 would undermine their ambitious Itanium project. Colwell revealed that he was threatened with termination twice for advocating the need for 64-bit x86 support, with management directly ordering him to remove the 64-bit functionality from the chips.
This internal conflict at Intel highlights a classic case of corporate politics overriding technical innovation. While Intel's engineers had the foresight to develop backward-compatible 64-bit technology, executives were betting everything on Itanium - their clean-slate 64-bit architecture that promised superior performance but required abandoning decades of x86 software compatibility.
AMD's Market-Changing Gamble
AMD's decision to extend x86 to 64 bits was born from necessity rather than choice. They understood that if Itanium succeeded, it would effectively end their existence as a CPU company. AMD's engineers recognized that most users valued backward compatibility over theoretical performance gains, making the transition as smooth as possible by ensuring 32-bit applications ran at full speed on their new 64-bit processors.
The community discussion reveals how AMD's approach proved prescient. The Athlon 64 wasn't just a good 64-bit processor - it was an exceptional 32-bit processor that happened to support 64-bit computing. This dual capability made it attractive to enterprise customers who needed immediate performance improvements while maintaining the option to transition to 64-bit software when ready.
Technical Advantages of AMD64:
- Full backward compatibility with 32-bit x86 applications
- Native 32-bit performance without emulation overhead
- Doubled general-purpose registers (8 to 16)
- Improved power efficiency compared to Intel Prescott
- Seamless transition path for existing software ecosystems
The Enterprise Adoption Story
Data centers quickly embraced AMD64 processors for practical reasons beyond just performance. The power efficiency advantages were immediately noticeable to system administrators managing hundreds of servers. Intel's Prescott-based processors ran significantly hotter than AMD's offerings, creating real operational challenges in densely packed server environments.
Even traditionally Intel-loyal companies like Dell began incorporating AMD processors into their server lineups - a move that would have been unthinkable just years earlier. The combination of better performance per watt and competitive pricing made AMD64 an easy business decision, despite Intel's strong brand recognition in enterprise markets.
Intel's Reluctant Adoption
By 2004, Intel was forced to abandon their Itanium-first strategy and clone AMD's x86-64 implementation. They initially called it EM64T (Extended Memory 64 Technology) before settling on the Intel64 branding. Ironically, licensing agreements that allowed AMD to use x86 instructions also granted Intel the rights to implement AMD's 64-bit extensions.
If you don't cannibalize yourself, someone else will.
This episode demonstrates how even dominant market leaders can stumble when they prioritize protecting existing investments over embracing superior technology. Intel's reluctance to cannibalize their own Itanium project with internal x86-64 technology opened the door for AMD to fundamentally reshape the processor landscape.
The story of AMD64 serves as a reminder that in technology, backward compatibility and user needs often trump theoretical performance advantages. While Intel's Itanium represented impressive engineering, AMD's practical approach to 64-bit computing ultimately won the market by making the transition as painless as possible for existing x86 users.