I have a several VBA procedures that read and process large (+50M) data
files. I am trying to do everything I can to optimize the speed.

Up until now, I was unfamiliar with "personal macro workbook". I would like
to use it for some of the macros that I use daily, but are stored in
individual workbooks.

If I starting using the "personal macro workbook", when I process my my
files, will it slow my programs down even more?

I currently am using Excel 2003. Thanks in advance