Howdy. In my eight years working with Excel on the Windows side, it was never the size of the file that was a problem (unless over 80 MB). I had some that were 100+ worksheets, some with several thousands of rows of data. Rather what caused real problems were the number of formulas (many thousands), specifically those formulas that contained volatile functions (i.e. that have to recalculate after every change on the spreadsheet). In those cases, it helped to turn off auto calculation, then when done working, turn it back on and wait 15-20 minutes as it re-calculated.
The key was to examine carefully the design of the workbook. I took one that a co-worker had developed that was 25 MB and very slow. In just a matter of two days I redesigned it, had reduced the size to less than 9 MB, and it re-calculated almost instantly.
MacBook Pro 15†Matte, OS X 10.6.6
Scrivener 2, Mellel 2.7.3, DevonThinkPro 2, Accordance 9.1,
OpenOffice.Org 3.3, Notebook 3, Reunion 9, Tinderbox 5.6.1
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