Thank you Murray for these performance articles, they provide a good summary that relates to most of the performance issues that I've encountered.  I wanted to link the following documentation about the implementation of filesystem caching in certain scenarios:

http://docs.intersystems.com/latest/csp/docbook/DocBook.UI.Page.cls?KEY=...

I understand that implementing caching for certain types of files that Caché utilizes (such as CACHE.DATs) can lead to performance problems or worse.  This just seemed like a related topic to me that was worth a mention.