I know that Excel uses multithreading for calculation, but I could not find details about multithreading for matrix and array formulas, such as MMULT, MAP, REDUCE and the like.

I have two questions:

  1. Does Excel calculate different array formulas simultaneously? (e.g. several columns, each of which is a separate array formula with many rows)

  2. Does Excel ever use multiple threads to calculate a single array or matrix formula?

My experience suggests that the answers are:

  1. yes,
  2. no,

based on the fact that I can achieve close to 100% CPU utilization with about 10 independent large array formulas on a worksheet, but I haven't been able to go over 15% utilization with a single formula or several formulas dependent on each other.

The official documentation (https://docs.microsoft.com/en-us/office/client-developer/excel/multithreading-and-memory-management) is silent on this topic, is there any other source of information or some way to verify how multithreading works with matrix and array formulas?

2 Answers 2


According to this site, Excel calculates different formulas multi-threaded.

The page doesn't say anything about calculation of a single formula, so I suppose it always happens on one thread.


You can read this article and you can get the information about the Calculation process:


  • The linked page does not answer the question.
    – user175348
    Jul 21 at 15:32

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