You should expect a slow down when using array formulas or SUMPRODUCT used in
lieu of an array formula. Each calculation requires multiple -- perhaps 100's
-- of calculations "under the hood".

On Mon, 10 Jan 2005 11:47:07 -0800, jrusso
wrote:

Hello,

I defined some named ranges in one of my workbooks. I created another
worsheet that uses references to these named ranges to generate counts using
the SUMPRODUCT function. The result has been unacceptably slow performance
in this workbook when using the autofilter to filter by a particular value in
a particular column. I have the same problem when I manually enter a value
or paste a value into a cell and move off the cell. The application says,
"calculating" for about 4-5 minutes.
Is there any way to improve this performance to an acceptable levesl?

Thanks,
John