Excel element that slow down working

[littlepete]

hello

i have a general question about things that slow down working on excel :

1. i noticed that a column with numbers (2000 rows) and conditional formatting on each of those numbers,
depending on some conditions, slow down the whole excel filtering jobs ! (dramatically)

2. adding a formula to count all rows having the same number in that column as that of the active row has
the same result of slowing down in a huge way...

HOW COME ???
is there (in general) a way to avoid slowing down? which elements always slow down excel???

thanks !!!

 

[Michael M]

Have a look here, especially the post with the link to David McRitchies website !

http://www.mrexcel.com/forum/excel-...tional-formatting-slows-down-spreadsheet.html

For the 2nd question, it depends on what formula you're using !

 

[littlepete]

hello again

thank you for the links !
i read all in the links. and i'm glad a few things i did are good with the conditional formatting.

the second question about the formula is this:
it's a list of used sale cards, with columns for name, date of buying, using the card, bringing back the card, number of times used and a few more.
there is always a row for a "resume" in which i fill in all the good data i got.
the formula i use is to detect and count how many times the card with number X is used, X being the number of the card, mentioned on the active row, i only put the formula on the rows where it says "resume", not the others.

=countifs($I$7:$I$2200;"=*verw*";$K$7:$K$2200;"="&$K7)

column I is the column where it should say "buying date; selling date; resume,..."
column K is the column where the total of used times is put with the formula

curious to find out where i can get better !

all have a great weekend !
pete

Have a look here, especially the post with the link to David McRitchies website !

http://www.mrexcel.com/forum/excel-...tional-formatting-slows-down-spreadsheet.html

For the 2nd question, it depends on what formula you're using !

 

[Michael M]

The countifs would be the most efficient, I believe....but
I think it might speed up if you could maybe use a helper column OR find a way to improve the search for this criteria

$I$7:$I$2200;"=*verw*"