From memory, the Netburst team ignored power efficiency until power density concerns hard-capped their frequency targets (and this was on 180/130/90 nm!). Itan

From memory, the Netburst team ignored power efficiency until power density concerns hard-capped their frequency targets (and this was on 180/130/90 nm!). Itanium is often lazily pointed to as a failure by Intel, but in reality it was a hard task with decent execution. Intel attempted to build an ecosystem around an entirely new architecture. Emphasis on smart-compiler extracted instruction level parallelism, supported by wide but less superscalar hardware. In 2001. As an analogy, this is kind of like asking every driver to toggle a switch to manage the engine mapping while they drive. It could be more effective, but it's also a ton of work and relies on expertise being developed. AMD delivered what the market really wanted in x64: something that looked exactly like x86, with a few modest improvements, and some 32-bit scaling limitations removed. But no big changes. The Israeli teams are usually cited as the caretakers of the P6 (Pentium Pro) legacy, which evolved into the Pentium M, and eventually the Core architectures. They chose to optimize for power efficiency, and so didn't hit the same power caps the Netburst team did. Generally, the internet comments on this are armchair generaling with the benefit of hindsight. There are many reasons things could have gone differently. Sometimes two teams work equally hard, but one chooses a path that leads to success and the other one that leads to failure.