All,

I have a fairly large workbook containing about a dozen worksheets. There
are some fairly complex formulas including cross-worksheet references. A
single macro loops x number of times, changing fields and re-calculating all
formulas.

I have tested this spreadsheet on 9 different PCs and on two of them the
performance is 30 times faster than the other seven (i.e one macro execution
of the "Calculate" command takes about 1 second on the two speedy machines
versus about 30 seconds on other seven). The PCs are all dramatically
different: Intel vs. AMD, different levels of memory ranging from 128MB to
1GB, different video cards, same versions of Excel (2000), Windows 2000 with
SP3, etc.

I can't find a common denominator in the two machines that process it
quickly. One of the machines is an home-made AMD 1.3 Ghz processor with
500MB RAM and standard 7200RPM IDE disk. The other is an Dell Dimension
4400 with 256MB RAM.

Among the slower processing machines a
(1) a brand new AMD Athlon XP2100+ with 512MB of DDR RM
(2) a brand new Sony VAIO GRS700K Notebook with 512MB RAM and a 1.8 Ghz
processor.
(3) a Dell PowerEdge 1400 server with dual 800 mhz processors and 500MB RAM.

It doesn't seem like a matter of horsepower, specifically. Does anyone know
of any tools available for identifying performance bottlenecks in Excel
spreadsheets? Any other ideas on what might be causing this dramatic
performance difference?

Thanks for any help you can provide.

Mark D'Agosta