Computer Performance Introduction

This topic is all about computer performance and the things that effect it. It is easy to say that  you know how things like, RAM, CPU, GPU, etc effect the performance of a computer. But WHY do they effect the performance?

Here is the section from the arrangement documents that cover this booklet.

  • Description and evaluation of the following measures  of performance: clock speed, MIPS, FLOPS, and application based tests
  • Description of the effect the following factors have on system performance: data bus width, use of cache memory, rate of data transfer to and from peripherals
  • Description of current trends in computer hardware, including increasing clock speeds, increasing memory and backing storage capacity

Today was all about benchmarks. We established early on in the lesson that clock speed was not a good way of comparing computing performance. A computer with a 3GHz CPU may not be as fast a 2GHz, why? well the 2GHz CPU may be a multicore processor or the computer may have faster RAM, more cache etc.

  • The first benchmark we looked at was MIPS , however different instructions require different numbers of clock cycles and there is no standard for measuring MIPS.
  • Floating Point Operations Per Second (FLOPS), this is a better measure of performance as floating point multiplications are basically the same for each processor.
  • Application benchmarks, these vary from application to application. It may be for example, how long does it take a package to render a special effect on a photograph. For games  machines we often quote Frames Per Second (FPS) benchmarks. A modern game is set to a pre-set graphic mode and the number of frames rendered per second is then recorded, example. Specialist benchmarking software can also be used to test the whole system, this is the software demoed in class.

Here is the list of the Top 500 computers in the world. Did you notice that the comparison was Petaflops?