Well it seems to depend. With smaller less complex formulas/workbooks, it
seems to work okay, but as the complexity increases, the odds of the F9 key
working properly decreases. There has been numerous times in the past when
I have attempted to use the F9 key to calculate only to find that it didn't
calculate all the way through, so when MS came out with the Alt-Ctrl-F9 to
address this issue in Excel 2000, this made my life so much easier to work
with. I even tested the F9 in XL2000, and it still didn't work properly for
me, but then I have more complex worksheets and workbooks too.
For the set of workbooks that I have a huge number of calculations, they are
in an instance of Excel to themselves with the calculation mode set to
Manual, while other workbooks with limited number of calculations are in a
separate instance of Excel with the calculation mode set to Automatic. I
typically have 2 or 3 difference instances of Excel up on the computer at
one time unless I am testing things out that may need to be proven it's not
just a system resource issue.
Ronald R. Dodge, Jr.
Master MOUS 2000