@dolphin_jay: Here's me wondering if I just cracked a good part of it in the last 15 minutes. With reference to my note on "smaller file subsets" that handle this independently, XML.php is a good illustration of the problem:
If you open up /flash/XML.php and read through just the files it requires — no less than 16 external files required, and I dread the thought of going to look them all up to see how much processing overhead they may produce, aside the obvious memory consumption see more from all the unused functions loaded into memory.
Call the above action (four SQL queries) through the heavy XML.php at 5 second intervals, multiply by a few dozen users, and it's a small miracle if your server isn't crawling.
If you open up /flash/XML.php and read through just the files it requires — no less than 16 external files required, and I dread the thought of going to look them all up to see how much processing overhead they may produce, aside the obvious memory consumption see more