It also failed because, at least 6 years before Itanium was even released (2001), there were better, faster options available. In 1995, the Pentium Pro feature

It also failed because, at least 6 years before Itanium was even released (2001), there were better, faster options available. In 1995, the Pentium Pro featured out-of-order and speculative execution[1]. This has two main advantages over the VLIW architecture (Itanium in particular): 1) The processor can use runtime information (such as past history of branches) to speculatively execute hundreds of instructions before they are needed. 2) When a stall happens due to a cache miss, in some cases the CPU can continue to execute instructions while waiting for the stall to end. This isn't possible with VLIW because the compiler can't predict cache hits/misses, this information is only available at runtime. These two advantages combined made Itanium much slower than the then available x86 processors. [1]: Note that Intel didn't invent these ideas. OoO was already known in the 1970s, although it was applied to mainframe supercomputers. I'm just using Pentium Pro as an example of a similar microprocessor.