Out of curiosity I tried the formula with 65536 cells and it was almost
instantaneous on my laptop which is a Pentium 4 processor (2.93GHZ) with 512
MB DDR RAM (so nothing special).

So try it!

"Randy" wrote:

Does Excel look at every cell in the range while performing calculations? I
have the following array formula and am wondering if it will slow things down
if I change the 12000s to 65536s. By changing the number I would not have to
worry about missing any data but then again if it is going to burn my cpu up
I will leave it as is.

=AVERAGE(IF((SCMatrix!$C2:$C12000="NOW")*(SCMatrix !$Y2:$Y120000),SCMatrix!$Y2:$Y12000))

Thanks!

Randy