PowerPivot FILTER condition optimizations

In the comments of a recent post from Alberto Ferrari there was an interesting note about different performance related to the order of conditions in a FILTER call. I investigated about that and Jeffrey Wang has been so nice to give me some info about actual implementation that I can share on a blog post.

First of all, an important disclaimer: PowerPivot is intended to make life easier, not requiring the user to think how to write the order of elements in a formula just to get better performance. To achieve this goal, following releases of PowerPivot could have a smarter engine that will not require the author to worry too much about how he writes a DAX expression!