Please forgive me for what even sounds like a silly question, to me!
If a software spec call for a minimum processor speed of 3.1 GHz, is that referring to a single core speed? With dual, or quad cores, is that speed load shared so that, say, an i5 with a speed of 2.3 GHz, or an i7 with 2.0 GHz, spread the load to acheive the higher speed, between them? Or have I "got the wrong end of the stick"
The clock speed of a CPU is just that regardless of whether it is single, dual or quad core or i3 or i7. A multi core CPU will spread the load, run cooler and perhaps be quicker, but the actual speed at which a CPU works will be the same.
Have a look at this link Click here it is more up to date than those posted above.
Multicore processors allow multithreading, i.e. two, four, six things to be done at once. This therefore speeds things up considerably meaning you don't necessarily need fast clock speeds to achieve the same results.
That said for multicore processors to function to their best the software must support multithreading.