Charles Williams

Charles Williams is an Excel performance expert who who blogs at FastExcel, where he says his objective is to "to share my experiences in my never-ending quest to make Excel go faster!" Charles also publishes Excel speed optimization tips, information on Excel's recalculation engine, and a commercial utility called FastExcel on his website Decision Models. He has some great tips and advice for optimizing formulas and UDFs (User Defined Functions) for speed. Check out Why 2 VLOOKUPS are faster than 1 VLOOKUP and Making your UDFs Efficient.