Negative Effects of Multitasking like Hard Disk HDD Thrashing

People often feel the negative effects of multitasking.  E.g. They waste much brain power thrashing.

They work one task too little. Then they switch to one more. Then to one more, and so on. They work lots of problems.  But they end up solving few, since they’re too busy switching between them.

The switching itself takes time, which is one of the negative effects of multitasking.  The person must “ramp down” from one task, and then, “ramp up” to the next one. This repeated ramping cost brain power.

Now if we switch tasks too much, then we accomplish too little real work.  We use more energy switching (mental thrashing) than doing jobs.  Without control thus, task switching becomes useless.  Lost yield is one of the other negative effects of multitasking.

Negative Effects of Multitasking in Computers

Hard Disk Thrashing

Computers also suffer the negative effects of multitasking.  This appears in them as hard disk thrashing.   To understand how the bad effects of too much task switching many look like mental thrashing in humans, read on.

The swapping of one running task to the next in the computer, demands overhead. It consumes memory to recall where it left off last in the prior program. It also retains where to pick up running in the next program. The code to run next must load into main memory from the hard disk. Further, the stack and CPU registers must restore their values the last time this program ran. Finally, the program counter must load the address of the next instruction to run in that reloaded program. Once that’s all done, the next program runs.

So indeed, there is quite a cost of switching tasks in computers.

How a Computer Multitasks

Now we won’t delve much into why one program stops running, to allow the CPU to run others.  But in short, this task changing approach assures that each program runs a fair amount o time.  To ensure fairness here, each program runs for a small period of time (called a time slice). When that time runs out, the computer jumps to the next program to run.  the CPU must switch context again. It then again incurs the same overhead just described, to resume the next program running. The shorter the time that the CPU spends running programs before it switches, the more time it spends switching.

Hopefully it’s clear.  When programs run for very small time slices, that the amount of real work done falls to zero.  When the CPU takes too much time switching context, we call this condition  thrashing. Thrashing is undesirable in computers.  Why? Because it burdens the CPU and cuts the computer’s performance.

Negative Effects of Multitasking in Humans

Mental thrashing likewise, has the same wasteful effects in the brain.  Too much switching from one thought to the next, slows one’s skill to solve problems. Recalling where you left off in a task demands time. Plus, you then must use that time refreshing your memory when switching among many tasks.  This is just what the CPU does when it switches tasks. This excessive mental thrashing frustrates therefore. This condition shows up in those who have trouble focusing.  They cannot attend enough.  This therefore, is among the negative effects of multitasking.

But, the longer we work a single task before interrupted by another, the better we work, to a point.  Thus, to maximize our effectiveness therefore, we must avoid overscheduling ourselves. Too many tasks in the queue over burdens us.  So, we should not allow obsessive task changing to consume too much mental bandwidth, and hinder real results.

Negative Effects of Single Mindedness

Too much single mindedness is yet another of the negative effects of multitasking.  So when trying to reduce these in mental thrashing, avoid growing too single-minded. Too much singular focus saps our mental yield as well.

Again, we draw on the computer example.  It’s good in the computer when the CPU spends  enough  time running each program.  But too much time in one, indeed starves the others. For instance, we saw these negative effects of multitasking in older versions of Microsoft Windows. In that case, poor safeguards allowed one program to take over the central processing unit (CPU)  and hard disk.  Then, other programs in the system ran not at all.

Further, this swamping showed up as system hangs, lock ups, slow running, or strange behaviors. It sometimes needed a reboot to clear. But these days, with real mode programs things of the past, computers handle task weighing much better.  Besides, with the growth of protected mode programs, task switching became much fairer.  So nowadays, it’s harder for faulty software to prevail in the system.

Indeed, there are negative effects of multitasking from concentrating too long on a single problem too. But few people ever see these symptoms of extreme single-mindedness. They more often feel the effects of mental thrashing instead, by not focusing enough on each task.  By in large, people hurt due to lacking focus rather than too much of it.

Reducing the Negative Effects of Multitasking

If the brain indeed mirrors a computer CPU, then we should reduce the mental thrashing we do.  So, to maximize the real work it does, and reduce the negative effects of multitasking, avoid it where sane.   But remember that occasional task switching is also good.  So long as we do not switch too much, task switching keeps us from growing bored with a single task.

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Revision History

  • 2018-03-07: Updated content.  Added the References and Related Posts sections.
  • 2015-12-18: Added more appropriate tags.
  • 2015-10-06: Added appropriate tags.
  • : Added whitespace, adjusted ad placement, and tweaked the content.
  • 2012-08-15: Published.