jfbus writes "PHP, like all scripting languages, suffers from having to parse all script files each time a page is displayed. Accelerators (opcode caches) are necessary to speed PHP enough for large websites. Here is a benchmark of the major PHP accelerators (Zend platform, apc and eAccelerator)."
I think there's a world market for about five computers.
-- attr. Thomas J. Watson (Chairman of the Board, IBM), 1943