Alex, the second advice is important. My site was heavy in the evening and I noticed that 'load average' regularly exceeded 2.00 because of MySql, when I saw at the same time via Google Analytics a display rate of 40 pages / minute.
I just went from MyISAM to InnoDB and applied the code change, under the same conditions, I get 'load average' 0.40 maximum and the site is very responsive. I did not expect so good results. Thank you !

Baloo did this really make your site load faster?

Yes, really +++ tonight it was very nice to sail, it's been a few weeks since it was not the case. I did not say anything, several members told me, did you do something? he is faster. Now, you have to see what is stuck in your home. You can run the 'top' command in a terminal and see if MySql is stuck.

Nice!!