The human brain is an extraordinary computing machine. Nobody understands exactly how it works its magic but part of the trick is the ability to store and process information at the same time.
That’s entirely unlike conventional computers which store information in random access memory or on hard disc and shuttle it back and forth as required to a central processing unit.
The time and energy all this takes is the thing that ultimately limits conventional computing performance, the so-called von Neumann bottleneck. Essentially, it is this that prevents conventional computers from approaching the performance of biological ones.