# Benchmarks

Some benchmarks, run on an ancient Thinkpad running Intel Core 2 Duo at 2GHz.

|Implementation     |  Time (sec)|
|-------------------|-----------:|
| Markdown.pl       | 2921.24    |
| Python markdown   |  291.25    |
| PHP markdown      |   20.82    |
| kramdown          |   17.32    |
| cheapskate        |    8.24    |
| peg-markdown      |    5.45    |
| parsedown         |    5.06    |
| marked            |    1.94    |
| **commonmark.js** |    1.93    |
| discount          |    1.86    |
| sundown           |    0.33    |
| **cmark**         |    0.33    |


To run these benchmarks, use `make bench PROG=/path/to/program`.

The input text is a 11MB Markdown file built by concatenating the
Markdown sources of all the localizations of the first edition of
[*Pro Git*](https://github.com/progit/progit/tree/master/en) by Scott Chacon.

`time` is used to measure execution speed.  The reported
time is the *difference* between the time to run the program
with the benchmark input and the time to run it with no input.
(This procedure ensures that implementations in dynamic languages are
not penalized by startup time.) A median of ten runs is taken.  The
process is reniced to a high priority so that the system doesn't
interrupt runs.

Note that these benchmarks were done on a 32-bit machine.  On a 64-bit
machines, sundown is significantly faster than cmark (0.146s vs 0.237s
on Intel i5/OSX with Clang, 0.130s vs 0.191s on a 64-bit Debian VPS
with GCC).  I do not know why the performance difference shows up on
the 64-bit architecture and not the 32-bit, but that is something that
might be investigated.