If you consider how most disk drives work, basically one reading processor, the disk that is being read applies the programs within in a 'linear fashion'.
If you had two reading processors, you could apply the programs within in an 'ordered fashion'.
Basically what this means that the more readers that you have, the more options you have for ordering the programs or tasks. This makes things much more efficient, saves time and energy.
You can imagine the mind working like this, picking on stuff from here and there, and deciding to order one's actions based on priority, timing, and favour.
In addition to that, the mind also does something quite interesting... When we think of the options before us, we consider so many of the options and how they work together. There are so many permutations of how, when, where, and why we will act.
It can be clearly seen that a multi-processing mind would work hand-in-hand with permutative thought.
For example, consider that moment real early in the day where you tell yourself all that you have planned to do for the day... and you start thinking of all the possible ways and times you will do things... until finally you have an agenda and can go through the day mostly scripted...
Basically you have processed many actions from many different areas and considered the permutations until you start prioritising, timing and favouring particular ways the day should go, and what to do.
Again, knowing more about the mind is one step closer to expanding your mind. One thing is, that, you have the basic operations you need to focus on.