Hi Adrian
I've noticed that this is a cross-post from "Windows-based servers": http://moodle.org/mod/forum/discuss.php?d=174209 (see http://docs.moodle.org/en/Moodle.org_forums_Code_of_Conduct#Post_your_question_in_one_forum_only ).
Please follow up the discussion in that forum.
Hardware and performance
Moodle and its PHP accelerator
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