Itanium is based on the EPIC architecture (not to be confused with AMD's EPYC processors) which is an evolution of the VLIW architecture. VLIW architectures ar

Itanium is based on the EPIC architecture (not to be confused with AMD's EPYC processors) which is an evolution of the VLIW architecture. VLIW architectures are based on the idea that instruction scheduling should be fully done at compile-time rather than mainly at run-time like modern superscalar processors do. Compile-time instruction scheduling removes a lot of logic from the circuit and therefore potentially consumes much less energy. However it requires more logic on the compiler side. But it's still today very complicated to build efficient VLIW compilers. Apart from very specific tasks like signal processing, VLIW & EPIC architectures has been abandoned.