Harry Fuecks, who runs the excelent phpPatterns site talks about object oriented programming and performance . He states that procedural PHP leads to slower apps and challenges everyone to prove the opposite.
Harry argues, the argument of procedural code beeing faster
is based on benchmarking code. What it ignores though is the human aspect of writing code and that's where a side-effect of OOP can result in improved performance.
Bearing in mind I'm talking only in a general sense, I think the tendency with procedural code is to use "brute force" - the actual meaning and behaviour of the logic being masked by the spaghetti. If what the code was actually doing was transparent to the developer, they might see some of the "blinding" inefficiencies they've introduced.
I totally agree. As I already argued regarding C++ optimization, performance is rather a question of design, not code.