I would argue that we pretty much reached peak single-core x86_64 scalar instruction stream concurrency ~6 years ago with Sandy Bridge. SIMD has gotten wider si

I would argue that we pretty much reached peak single-core x86_64 scalar instruction stream concurrency ~6 years ago with Sandy Bridge. SIMD has gotten wider since then (AVX2, etc) and there are occasional new instructions for certain workloads (including FMA as you noted), but general purpose scalar (non-SIMD) workloads have not gotten much of an IPC boost. Actually, to the extent that those workloads have gotten faster, it's been mostly from the return of clock frequency scaling - from low 3GHz to low 4GHz on the desktop SKUs.