A while ago I noticed Jordan Mantha repeated my old bzr vs git benchmark.

I was curious to see if things changed. It seemed that both systems have improved in speed, but there were no shocking results.

There are some differences between our experiments though. Jordan wonders how long it took for me to commit my changes after adding. In fact, I didn’t do that directly but did a diff before committing. I don’t know why, I think I just forgot to commit. This clearly showed the big difference between bzr and git before and after committing. Bzr was a lot faster than git before committing, while git outperforms bzr after committing. I guess this is because git makes heavy use of data structures created during a commit.

Bzr took almost 4 minutes to diff after committing, while git only took about a second. This clearly showed a problem with bzr, it started walking the entire tree again, while git could immediately see that nothing changed. Bzr exacerbated the same problem when performing a status, it was unnecessarily slow. Jordan’s tests showed that the status problem was solved, but doing a diff when nothing has changed is still a major performance issue on big trees.

Committing a small change was a lot faster for both git and bzr. And it should! This is after all a really common operation.

Jordan did another comparison with bzr, git and hg, which showed that hg is actually fairly close to git in terms of performance.