Following on the heels of his previous post, Micro Optimizations that Matter, Brandon Savage has taken on all of the articles out there that tout several common misconceptions about what micro-optimizations make your scripts really run faster in this new post to his blog.
Last week I wrote about some optimizations you can apply to your code that will improve the performance of your site significantly. I also mentioned that regularly an article pops up talking about ways to shave time off your scripts, and I talked about how these articles mostly are bunk. Like this one. The article I linked above is a run-of-the-mill micro optimization list. The difference here is that the author actually makes use of some benchmarks to make their point. So, let's go step by step and discover together why this article takes longer to read than the amount of CPU time it saves.
He covers a few different categories including looping, quotes in strings, echo versus print, pathing, timestamps and using the regular expression functions (like ereg_* and preg_*).