Help speed up slow INDEX (SMALL function

Hi all,

I have a function like below:

INDEX('Sheet1'!$B:$B,SMALL(IF(IFERROR('4'!$A:$A,0)=$C$9,ROW('Sheet1'!$A:$A)),COLUMN(A1)))

The goal of the function (I drag it horizontally across multiple cells) is to return multiple results that have the same value as cell C9, thus the SMALL function instead of INDEX/MATCH. However, this slows down my excel tremendously, and am wondering if there are faster functions out there to do what I'm trying to do? Not sure if it's relevant, but I have this function array-entered now, as it doesn't appear to work without that.

Thanks!

Heh, actually found a solution to my own question--for anyone else wondering, don't use A:A for location, but limit it to how much data you have, such as A1:A300. This speeds it up tremendously.