Copy paste slow due to vlookup if error

Hello,

why does Excel is slow when pasting text? I know it is the recalculation thing default enabled. But because I cannot turn it off for certain cells (only for the whole sheet or app) I need to ask what makes excel so slow here?

I have in B2 and C2 cells where I paste my text (I paste it into these cells). In the H row for every cell there are these instructions:

Iferror vlookup & Iferror vlookup & Iferror vlookup & Iferror vlookup & - These instructions load other text from other sources. I use it only once to load other text source.

I noticed that if I delet all those instructions, copy paste would be instant - without a "thinking" circle and delay of 2 seconds.

The question is - why do these instructions have impact on something that they are not even related to? These instructions do not even mention B2 and C2. Yet leaving them makes copy paste slow even in the X1000 cell.

Hello, this would not answer your question,
but as far as i knew, index match is faster & lighter than vlookup.

If you are trying to do a VLOOKUP in entire column it will slow you down, but at least post your formula for us to check.