[IPOL discuss] about performance comparisons in IPOL articles

[Miguel Colom]

Quoting Nicolas Limare <nicolas.limare at cmla.ens-cachan.fr>:
> Dear all,
>
> When you compare software performances in an IPOL article, please be
> precise. Saying that "program A is twice as fast as program B" is not
> verifiable. I think that, to be meaningful, one must at least provide
> this information:
> * exact version of the codes
> * exact compiler version and compilation options
> * harwdare model, at least the CPU (model and speed) and RAM (size and
>   speed)
> * if and where some parallelism is involved
> * operating system type, model and version
> * version of important libraries used by the code if relevant
> * input data, parameters
> * how the performance is measured

I agree with this.
However, I think that a fair comparison of two algorithms shouldn't be  
only based on the execution time, but on the complexity analysis.

The "big O" [1] notation seems a good measure.
The Wikipedia shows a plot that could be a real case: the algorithm in  
blue seems to be better than the red if it's executed within a small  
time. But if the execution time increases, the red is clearly better.

Best,
Miguel

[1] http://en.wikipedia.org/wiki/Big_O_notation