Hi

I have been using the expression =SUMPRODUCT(--(file'!$P$1:$P
$65500="txt");'file'!$H$1:$H$65500)
to summarize all cells in column H where column P= "txt"

I have 1200 of theese expressions and it make the startup and
recalculating very slow (3-4 minutes)

The 65500 is choosed to be sure that I never ran out of Data and it
was not based on an analyze.

To optimize this cut the 65500 down to a relevant size ( ex. 10000)
and then the calculation time is reduced dramatically.

regards

Kurt