I have 13 columns of data with 30000 rows. Most data is numeric some is
2 words at the most.

The computer calculates cells very slowly and sometimes will not save
due to insufficient resources. I have 1gig ram.

An example formula might be.

=sumproduct((month=a1)*(year=a2)*(salesperson=a3)* (sales)

I may have as many as 120 of these formulas on a sheet referencing 12
different salespeople and 10 other key perfromance measures.

Is there anything I should look for or change to speed it up?
What about save and calculation options on the tools/options tab. I
dont know about these.
Would it be faster if my dbase and my worksheets are in separate books?
or does sumproduct "LOOK" anyway?

Any help would be greatly appreciated.