Why does Excel VBA run significantly faster when Outlook is closed?

Question

so I have been noticing the VBA code I have written runs significantly faster when Outlook is closed. This is not a sporadic thing: I can run the same code 10x with Outlook open an experience significantly slower processing speeds each and every time, then close Outlook and run 10x and experience significantly faster speeds each and every time. I have also noticed that in addition to Excel "not responding" while code is running, the same goes for Outlook sporadically. I know that Outlook is powered by Word, so it would make sense to me if I was running code in Word. However my Excel VBA in no way utilizes Outlook nor Word. What could the cause of this be? Do Excel and Outlook share some of the same process? I've tried Googling to no avail.

Answer 1

I also have experienced this issue.

Both Outlook and Excel are part of the Microsoft Office suite, so I believe the delays boil down to memory sharing between the MS suite programs when they are being used.

When you run a macro, it tends slows down the all MS suite program operations (in my experience). The only real solution I have come up with is to close down MS suite programs before running large macros, including Word and Outlook. I hope this helps.

P.S. Please post your code, I might be able to help you speed it up.