I'm looking to add what's basically a small chunk of rotated content ("this week's feature" sort of thing) to the sidebar of a site of mine that currently consists of static pages built out by a somewhat custom backend. I've been debating whether to do this as an iFrame, via an SSI include, or a PHP include. Or, maybe just rebuild the whole set of pages every week if I really need to. What's weird is that I can't seem to find any sort of benchmark past unfounded generalizations as to which is faster, which has the lowest CPU overhead, and (possibly most importantly) what the relative speed difference is between them. That is, it's not clear to me whether an SSI parser is going to take longer and more CPU overhead to process a, say, 50KB page vs using a PHP include on the same file, and if the relative increase in CPU hit vs. a "bare" HTTP request is large enough with either to care about. I mean, if feeding the page to PHP and doing a couple of small includes with no database access or other logic is only going to add 20% of the CPU seconds over a bare Apache request, it wouldn't really matter, but if it's a factor of 5, then that's more significant. Similarly, while I know the user-end time to do another HTTP request for iFrame content is significant, I don't know what the associated Apache overhead for another request is. Does anybody have any suggested reading with some concrete numbers on this stuff? Or, alternately, any suggestions as to a decent benchmarking technique so that I could run a few hundred requests and see what the reality is?