VBA + Excel Performance: Your Feedback Requested…

The Excel blog is back after a short break for the holidays.  Happy New Year!  Today’s post comes from Chad Rothschiller, a Program Manager on the Excel team, who is looking at ways to improve performance in the next version of Excel.

The Excel development team is currently investigating a number of scenarios where VBA macros take longer to run in Excel 2007 than in earlier versions (i.e. Excel 2003). 
We are looking for folks who believe they have run into a VBA performance slowdown and who would be willing to share their code/workbook/steps to reproduce the issue.  Given the enormous variety of solutions people build in Excel using VBA, we think it is important to survey the Excel community to collect a range of examples that are important to Excel users.
Specifically, we are interested in looking for VBA code that takes longer to run in Excel 2007 than in previous versions of Excel.  Other than that, pretty much anything goes with respect to feature & code usage.  To successfully analyze any problem, we really need to be able to run the code & reproduce the problem in-house, so the more specific and helpful the comment, the better.  General comments about something slowing down, without the example code that demonstrates the issue, can prove difficult to isolate and analyze.
A couple notes:

  • Don’t forget to send us the workbook as well, if it contains data or a certain structure required by your code (for example, if your code assumes particular sheet names).
  • If you can’t send us the whole solution, or if you need to simplify the code at all, please keep in mind that those changes can end up altering where the performance bottle neck occurs, create new bottle necks, etc. In these cases it would be really helpful to also send us:
    • a description of what the original code is doing,
    • what sort of slowdown you are seeing on your target systems

… this simply helps us reproduce your results in-house.
We have already taken a look on the web for reported issues and followed up with some folks, but if you’ve already posted comments publicly, it wouldn’t hurt for you to let us know those links just to be sure we’ve covered those.  Anything submitted will be treated as 100% confidential and used only for our own internal performance testing.
Folks can send files or descriptions to: xlfiles@microsoft.com.  If emailing files will not work, contact us and we can make other arrangements.  Once we have the code / solutions, we will baseline their performance in earlier versions of Excel and then run it on a set of test machines using the version of Excel that’s currently under development, and compare the results.  Thanks in advance to anyone that sends in examples.