In Poor Charting Performance in Excel 2007 I compared the charting performance of Excel 2007 to that of Excel 2003. I did this by recalculating the random numbers used as chart data for XY and Line charts with 100 to 1000 points, and averaging the time it took to recalculate 100 times.
I used Virtual PC to do my testing, using two virtual machines with Windows XP SP2 running in 513 MB, one with Excel 2003 SP3, the other with Excel 2007 SP1. Robert Kosara wondered whether using only 513 MB was strangling Excel 2007. I changed the settings on the two VMs so they each used 1023 MB, and I reran the tests.
Running in a larger memory space did help Excel 2007. The XY charts showed an improvement of 11-20% in redrawing time, while the line charts showed an improvement of 19-34%.
The larger memory also helped Excel 2003. The XY charts showed an improvement of 12-20% in redrawing time, while the line charts showed an improvement of 15-30%.
Excel 2007 is still about an order of magnitude slower than Excel 2003.
The test results can be read in ChtPerf2003v2007ram.csv. Here is the pivot table of the data.
Here is a comparison of 2003 and 2007 XY charts. Both versions of Excel experience an improvement with 1023 MB over 513 MB, but the ratios between 2007 and 2003 redrawing times are essentially unchanged.
With 1023 MB of RAM, the Excel 2007 XY charts take 8.5 to 11 times as long to redraw as the Excel 2003 XY charts.
Here is a comparison of 2003 and 2007 Line charts. As with XY charts, the Line charts show some improvement with 1023 MB over 513 MB, but the ratios between 2007 and 2003 are essentially unchanged.
With 1023 MB of RAM, the Excel 2007 Line charts take 15 to 22 times as long to redraw as the Excel 2003 Line charts.
Overall, charts in Excel 2007 are redrawn much more slowly than those in Excel 2003.
Update October 10, 2008
In a comment in a related post, Simon Murphy wondered how much of the chart redrawing discrepancy was due to slower recalculation in Excel 2007. I fired up the two VMs, and I ran tests measuring the time it takes to recalculate various numbers of cells. The results can be read in Excel 2007 Recalculates Slowly.