Modified Calibrator
Author: Marco Aurélio Graciotto Silva <[email protected]>


Calibrator was developed by Stefan Manegold ([email protected]) and can
be found at 'http://www.cwi.nl/~manegold/Calibrator'. The software can
discover the CPU's data and TLB cache size.

I discovered 'Calibrator' at undergraduation. The professor asked us, students,
to develop a program to discover the cache size of a CPU. I had a reasonable
knowledge about x86 compatible CPUs and their caches, and I figured out it
could, somehow, be done by playing with the cache lines and measuring the
times. But that would be quite time consuming. The first prototipes were
definitely innacurate. 

That's when I found Stefan's work. At first glance, it was almost a miracle.
The data was (almost) always correct, the graphics (after gnuplot processed)
were a valuable resource.

However, the precision was not that great. It always guesses wrong the cache
size, usually one order less. Looking the graphics, it was easy to spot the
real cache size: the problem was just lack of precision.

So I started modifying the software. At that time, using version 0.9c, I
removed all the I/O instructions, the same one's used to build the graphs.
After one day, understanding the software and hacking it, the results
were amazing: it got the cache and TLB sizes correctly, always!

The professor was amazed with the results also. Actually, that was the
first time I got the max score in a laboratory practice. Calibrator teached
me too much to mention, it's a worthless tool for computer architecture
students.

Some time later, Stefan released version 0.9e. I updated my software to it
and, from times to times, I review it. Yes, it's a maintaned software. So
use it! Any doubt, email me (or Stefan).

Run 'make' to compile the application. Then run the 'calibrator' binary.
As arguments, set your CPU and as much memory as you have phisically
available.