mining is a very paralleled workload, therefore a CPU with more cores will benefit more than one with faster cores (as a single CPU core can only go so fast while being power efficient). This is why GPUs excel at mining as they have lots of "cores" although each one is a lot weaker than a CPU core, which is why most mining is done with GPUs. For CPU optimized algos (like the original CN) you are better off with a cheap Ryzen CPU as they offer more cores. Hope this helps, ask me if you need any more help or if i was unclear