For a project that we are currently implementing, we’ve asked ourselves what the best way to access the database would be. So far, a number of our projects had been realized with Pear DB, and that was mostly okay. The current project needs to be resonsive even under high server load, so we try to cut away all the slack we can. So we did a few benchmarks.
PDO, in certain cases, is up to 4 times as fast as Pear DB.