[nkozyra]

I know it's been mentioned above, but PHP is very much not slow on its own. On that particular benchmark it's the highest interpreted language on the list (same with single query, fortunes and data updates). In fact, despite some atrocious language design, speed hasn't been a problem in a long time. And that's just PHP5, PHP7 offers claims of 100% speedup, not to mention HHVM.

I would wager that the typical bottlenecks are where the slowdowns are happening, and your hints about the # and types of queries would be my first guess.