I have recently come across an excel workbook weighing in at around 25Mb. It contains 5 worksheets, each containing a moderate amount of simple =sum type formulas.

However, when opening then scrolling some of the 5 sheets, the CPU load jumps to 100%. Is this attributed to the formulas and/or file size?

I have tried executing and viewing the file on both a 2.2Ghz and 2.8Ghz P4 with both PC's limping in pain.

Can someone give me some background info on why this particular file would be doing this and what I can do, or look for to reduce lag times?

Many thanks.