Single core performance is the primary thing that determines responsiveness for many programs.
Yet it won't matter at <2%, especially when multi-core is actually slower.
> Single core performance is only useful for artificial benchmarks
That is nonsense that none of the CPU competitors would agree with. In most applications single core performance matters very much. Not every algorithm can be multi threaded and there is an unavoidable overhead with those that can be multi threaded. Only some parts of some applications can be multi threaded.
For example, a 20 core 500 MHz CPU is much less capable and responsive for real world usage than a 5 core 2 GHz CPU, despite having the same instruction count per cycle.
A 100 core 100 Mhz CPU would take forever to boot up and feel unusably slow.
Single core performance is only useful for artificial benchmarks. And even there Apples lead is less than 2%.