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← 02-11 Simplifications For Ram

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Showing Revision 1 created 10/03/2012 by Amara Bot.

  1. As you can see, exactly counting the number of time steps
  2. even though we have a very simple model of just three rules
  3. and a code that doesn't even have a variable input is already quite tedious.
  4. We are going to introduce a number of additional simplifications
  5. that will give us a little more levy here so that we do not have to go
  6. through this exact counting process but still learns something about the algorithm.
  7. In general, the capabilities of the RAM closely matched what you would expect from
  8. your own computer but of course it is a simplification
  9. but nevertheless it is a rather solid model.
  10. It's difficult to design an algorithm that when you analyze it
  11. it will give you a very different idea about its performance that it would get on the RAM.
  12. Nevertheless, I think it's important to think about the differences
  13. between a RAM model and a normal computer, and we will do this as a quiz.
  14. Here are four main simplifications that I think the RAM is making.
  15. Here are four properties of the RAM.
  16. The first one is simple operations take only one time step.
  17. The second one is we assume that we have as much memory as we need.
  18. The third one is that memory access is considered to be free in terms of time.
  19. And the fourth one is that a unit of memory cannot hold an arbitrarily large number.
  20. And of course this is going to be subjective, but I would like you to tell me
  21. which of these four properties you think is realistic in the sense that it comes pretty close
  22. to a real computer and which of these you would consider unrealistic
  23. meaning of you were to run your algorithm on a real machine
  24. then there would be considerable differences and again the answers to these are subjective.
  25. If you get stuck or if you disagree with me just take next and see where our opinions differ.