Super User is a question and answer site for computer enthusiasts and power users. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

During my time spent working with multiple machines, I have noticed that performance of the same machine doing the same tasks in the same order differs and sometimes the difference is big enough to be noticeable. This applies to all the machines I've owned and/or maintained (old and modern). Some examples (many of them you may have noticed yourself) that sometimes are completed in different time frames:

  • POST
  • OS installation
  • Hardware tests and operations (usually executed within a customized OS such as one of the many DOS variants), HDD tests and "low level" formats
  • Software installation or other tasks (such as benchmarks) within a general purpose OS (Windows, Linux, etc)

I can imagine this is caused by the fact that a machine is built with many components having to communicate as a whole and since the mechanical and electronic parts aren't perfect the overhead occurs. In the last example, I assume the OS complexity and concurrently running multiple processes has some additional effect as well. However, I'm wondering if this hardware imperfection and overhead is indeed that high to be humanly noticeable? Maybe there are other factors that are influencial as much or even more? So, in short - why?

To emphasize: the difference is noticeable on the same machine performing the same tasks and this applies to ANY machine in my experience. I'm not comparing machine to machine performance.

share|improve this question

Hardware imperfections are not normally noticeable. However harddisks are an exception. If a harddisk is going bad it might significantly affect performance since it might be working for longer to read or write data.

The most likely reason for this is heat buildup and various powersave modes like intels speedstep and similar stuff. You might also have a "intelligent" overclocking feature enabled for your motherboard(s) that might boost / reduce speed at will.

share|improve this answer

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .