Excel 365 2501 Build 64-Bit Won't Use all processors - reverts to using Manual 4

Question

Not sure when this started happening, but with Excel I am able to set the processors to Manual to 4, but when I update to 6 or set to Use all and Save the workbook and open again the Manual of 4 is selected again. Not sure why I can't save using either All or say 6 when Excel thinks I have 12.

Answer 1

Hi @Doug Rosencrans

Does this issue exist in all Excel workbooks?

Do you run macro, UDF in the workbook?

I suggest you switch the workbook calculation option for a check.

Then disable all the COM Add-ins for a check.

Please click File > Options > Add-ins > Manage COM Add-ins in Excel, click Go, clear the check boxes for any enabled COM add-ins, select OK, and then check this issue.

But I want to say Excel runs with a single thread most of the time, Excel offers multi-threaded calculations for certain functions, such as matrix operations and statistical functions. The most important factor that influences Excel calculation speed is still the way your worksheet is designed and built.

The reference:

Multithreaded recalculation in Excel

Excel performance: Improving calculation performance

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Answer 2

Looks like the problem was a macro enabled workbook in the startup folder that had manual set at 4. I removed the workbook and the workbooks that are now openned have their correct settings.

I'll experiment with that workbook.

Weird.

Thanks,

Doug