This post is based on an answer by Glyn Williams to the question “Do we really need octacore CPUs in our smart phones?” that appeared originally on Quora.
Most phone apps (and most apps of any sort) tend to use one main thread and perhaps a secondary loading thread. This means for regular single-tasking, dual core is all that is needed. It might make sense to add another one or two cores for heavier duty uses. But the benefit is limited.
And before anyone points out that multi-tasking is awesome, you really don’t want multiple apps running in background draining your phone battery.
Multi-core processors make sense for high performance computing applications, where the same task can run on as many cores as possible. Not all tasks can be divided up like this. Rendering 3D graphics, running a web-server etc. – mean the more cores the better.
But in the handset, a thousand cores will not load Facebook any faster than two.
(In truth the “8 core” mobile CPUs are actually dual 4 core processors, with both low and high power versions of each core. 8 cores are never in simultaneous use.
In other words this is marketing hype.