Not really. In most cases your software is single threaded anyway, unless you implement some sort of parallelism yourself and when you do that it usually should

Not really. In most cases your software is single threaded anyway, unless you implement some sort of parallelism yourself and when you do that it usually should make sense. But in the end its the OS thats shuffles the threads around on the cores. If you disable a core, the others can run faster reaching higher clock speeds which might or might not be benefical to your program depending on the work it does.