Jeff keeps telling me that it is a hassle to find the posts in my series on writing efficient VBA UDFs. So Here you are Jeff: a headline page.
There are currently 22 posts in this series. They sort of follow a logical sequence, although each one is standalone.
- Part1: Writing efficient vba udfs part 1: It ain’t what you do it’s the way that you do it
- Part2: Writing efficient vba udfs part 2: Using Excel Functions inside a UDF
- Part 3: Avoiding the VBA Refresh bug
- Part 4: Variants, references, arrays, calculated expressions, scalars
- Part 5: UDF array formulas go faster
- Part 6: Faster strings and byte arrays
- Part7: Why UDFs can be calculated multiple times
- Part 8: Getting the previously calculated value from the calling cells
- Part 9: An example UDF
- Part 10: Volatile functions and function arguments
- Part 11: Full column references in UDFs used range is slow
- Part 12: Getting used range fast using application events and a cache
- Part 13: Maxminfair allocation an array UDF example
- Part 14: Handling whole columns using implicit intersection
- Part 15: Adding Intellisense to your UDFs
- Part 16: An example UDF calculating Gini coefficients efficiently
- Part 17: Inserting a UDF and calling the Function Wizard from VBA
- Part 18: Calling UDFs from VBA: Evaluate, Reference or Run?
- Part 19: UDFs for comparing lists: Dictionaries, Collections, Binary Search and Linear Search
- Part 20: Developing a faster Lookup UDF part 1 – using Excels functions efficiently
- Part 21: Developing a faster Lookup UDF Part 2 – the FLOOKUP UDF
- Part 22: Developing a faster Lookup UDF Part 3 – using binary search algorithms
Excel and UDF Performance Stuff 
Awesome! Jeff like!