> which is exactly the same per-core bandwidth we had in 2005. Modern CPU cores are way faster than ones in 15 years old CPUs. That 2015 processor has AMD K8

> which is exactly the same per-core bandwidth we had in 2005. Modern CPU cores are way faster than ones in 15 years old CPUs. That 2015 processor has AMD K8 cores. I wasn’t able to find exact info, but slightly newer AMD K10 can do 8 single-precision FLOPs/cycle, at 2.8 GHz. Modern Zen2 cores can do 32 FLOPs/cycle at approximately same frequency, i.e. per-core performance improved by a factor of 4. Both numbers are theoretical limits only achieved with very specific workloads and heavy use of manual vectorization. Still, real-life general-purpose code scales quite similarly between them. CPU benchmark says their single-threaded performance improved by a factor of 3.5.