I have a similar issue using Excel 2003 with array formulas.

My data file is ~30Mb (with approx 20,000 rows of data and 4 pivot
tables)

My analysis file is ~11Mb with 15 worksheets each with ~75 cells with
array formulas to read the data file above.

The re-calculation takes 5 minutes ordinarily with an IBM T40 laptop
with 1GB RAM. Specs are similar to the original posters

OS Name Microsoft Windows XP Professional
Version 5.1.2600 Service Pack 1 Build 2600
OS Manufacturer Microsoft Corporation
System Manufacturer IBM
System Model 237392U
System Type X86-based PC
Processor x86 Family 6 Model 9 Stepping 5 GenuineIntel ~1594 Mhz
BIOS Version/Date IBM 1RETB7WW (3.00c), 25/02/2004
SMBIOS Version 2.33
Locale Canada
Hardware Abstraction Layer Version = "5.1.2600.1106
(xpsp1.020828-1920)"
Total Physical Memory 1,024.00 MB
Available Physical Memory 619.55 MB
Total Virtual Memory 3.40 GB
Available Virtual Memory 2.72 GB
Page File Space 2.40 GB
Page File C:\pagefile.sys


"Charles Williams" wrote in message ...
Hi Fred,

You have enough RAM I think.

You dont say how large the data range is but assuming its 1650 rows *
?columns columns that would make

742500 * 3* 1650 multiplications =3675 million

The answer is that if you want to use SUMPRODUCT it will take a very long
time to calculate (you could leave it running over the weekend and it would
probably finish).

I suggest you look for an alternative approach:
- pivot tables would be good
- alternatively you need to do something like sorting the data and using
that to minimise the size of the range that you are using SUMPRODUCT on.

more suggestions on my website

regards
Charles
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