It looks like the Microsoft Exchange Team is working very hard on improving the Exchange Mailbox Role Calculator, because today they released version 4.5 (around 2 weeks after releasing 3.5). This version includes the following changes since 3.5:

• Included minimum number of global catalog cores in calculation results;
• Ability to specify different RAID parity settings for Restore LUN;
• Improved formatted capacity of a disk drive calculation;

Version 4.5 of the calculator also includes several bugfixes; consult the changelog (or should that be changeblog 🙂 ).

Looking at the number of changes and the changes itself I’m puzzled why the Mailbox Storage Calculator suddenly jumped 1 major version (3.5->4.5) where one would expect a minor version update.

You can download the calculator here.