Thought I might use arrays to collect chart series X and Y values from a mass
of data (simplified example code below)
I found that with simple integers I can load a maximum of about 140 values.
With DateTime numbers this comes down to about 16 maximum.
Is this to be expected? (Excel 2003)

Dim myChtObj As ChartObject
Set myChtObj = Sheets("chart").ChartObjects("Chart 1")
With myChtObj.Chart
.SeriesCollection(1).Values = Array(4,5,6,...,n)
.SeriesCollection(1).XValues = Array(1,2,3,...,n)
End With