In fact, hasn't been true since the Pentium Pro. Agner Fog's excellent microarchitecture docs [1] indicate that the PPro (which was a 3-wide machine, and the fi

In fact, hasn't been true since the Pentium Pro. Agner Fog's excellent microarchitecture docs [1] indicate that the PPro (which was a 3-wide machine, and the first out-of-order x86) could find 3 instructions per cycle out of a 16-byte fetch chunk, and likely did so by speculatively starting decode at each byte in parallel. [1] http://www.agner.org/optimize/microarchitecture.pdf http://www.agner.org/optimize/microarchitecture.pdf