The detailed model of the computer given in the previous section is based on a number of different timing parameters-- , , , , , , , , , , , and . While it is true that a model with a large number of parameters is quite flexible and therefore likely to be a good predictor of performance, keeping track of the all of the parameters during the analysis is rather burdensome.

In this section, we present a simplified model which makes the performance analysis easier to do. The cost of using the simplified model is that it is likely to be a less accurate predictor of performance than the detailed model.

Consider the various timing parameters in the detailed model.
In a real machine, each of these parameters will be a multiple
of the basic clock period
of the machine.
The clock frequency
of a modern computers is typically between 100 and 500 MHz.
Therefore, the clock period is typically between 2 and 10 ns.
Let the clock period of the machine be *T*.
Then each of the timing parameters can be expressed as an integer
multiple of the clock period.
E.g., , where , .

The simplified model eliminates all of the arbitrary timing parameters in the detailed model. This is done by making the following two simplifying assumptions:

- All timing parameters are expressed in units of clock cycles.
In effect,
*T*=1. - The proportionality constant,
*k*, for all timing parameters is assumed to be the same:*k*=1.

- An Example-Geometric Series Summation
- About Arithmetic Series Summation
- Example-Geometric Series Summation Again
- About Geometric Series Summation
- Example-Computing Powers
- Example-Geometric Series Summation Yet Again

Copyright © 1997 by Bruno R. Preiss, P.Eng. All rights reserved.