Dale,
First question: what version of Excel are you using?

First thing I'd suggest doing is taking the one sheet that has the data to
be charted and copying that sheet into its own workbook and graphing in there
and see if there's an improvement.

Quick Tip for future use: when you have a large spreadsheet and want to
convert ALL formulas and linked data to their values, first select all of the
cells on a sheet and use Edit | Copy; then, without unselecting the cells,
turn right around and use
Edit | Paste Special and choose the [Values] option. That will do it
quickly and painlessly for you. Repeat on any other sheets in the book you
need to do the same thing for.

"Dale" wrote:

I have a large workbook (14MB) that contains 3 months of 1 minute data in
three tabs that is cut and pasted from another spreadsheet that does the
calculations on the monthly data and another tab that calculates 1 hr
averages from the three monthly tabs. The workbook has been set to manual
calculation. When I add a simple line chart of the 1 hr average data (2 y
variables, date as text as the x variable) to the workbook, excel wants to do
"something" EVERY time I click the chart with a mouse. I look at Windows
Task Manager, and the excel process shows 25% usage (1 of the 4 CPU's maxes
out).

Thinking that the issue was the number of calculations occurring in the
workbook, I went thru a painstaking process of of converting all the
calculated data to values, eliminating all calculation in one version of the
spreadsheet. This did not resolve the problem.

Can anyone explain why this is happening, and what can be done to prevent
this from happening?