Forum Discussion
Terrible recalculation speed on Ryzen processor
Something has happened recently to my copy of Excel 2021. Perhaps it is an update, I'm not sure. My large spreadsheet model now takes 40 seconds to recalculate on my Ryzen 7 3700x, a 16 thread CPU....
After more experimentation, I found that if I disable multi-threaded calculations in the advanced options page, the recalculation time goes from 40 seconds to about 1 second. I don't want to speculative on why this happens. Thoughts of bloatware are going off in my mind. I've checked the calculations and all are accurate. Needless to say, I've disabled multi-threaded calculations in Excel. Perhaps this will help someone in the same situation in the future.
I've reported this to the Excel team.
Multi-threaded recalc occurs in 2 steps.
Step 1 works out how to allocate the calc between threads
Step 2 then actually does the calc.
Usually the results of previous Step 1 optimisations are used as a starting point for subsequent recalcs so the time taken to do step 1 diminishes on subsequent recalcs.
Difficult to make any sensible comments without looking at the actual workbook (would be happy to do that if possible)
Charles Williams
