You would be surprised how "slow" a non speculative processor is. Even Intel Atoms have been speculative since Silvermont. If you take more mainstream histori

You would be surprised how "slow" a non speculative processor is. Even Intel Atoms have been speculative since Silvermont. If you take more mainstream historical processors, for example: https://www.cpu-world.com/Compare/385/Intel_Pentium_Dual-Core_G6950_vs_Intel_Pentium_MMX_166_MHz_(A80503166).html https://www.cpu-world.com/Compare/385/Intel_Pentium_Dual-Cor... Let say the Pentium MMX 166 is roughly 60x slower, per core, than the Pentium G6950. So the "IPC" (I'm not sure of what the benchmark are doing, but I'm doing rough evaluations anyway) is approx 3.5 lower for the Pentium MMX. And that is while the speed gap constantly increased between memory and CPU (esp latency), so a Pentium MMX cpu core somehow speed up to 2.8 GHz would actually probably perform even worse in a design with memory that actually exists. Maybe way worse. The complexity of modern good ARMs is comparable or even higher in some area than the complexity of x86 processors.