doc: fs module: Callback API vs Promises API performance difference

[Eli-Argon]

📗 API Reference Docs Problem

• Version: 16.7.0

Location

Affected URL(s):

• https://nodejs.org/api//fs.html#fs_callback_example

Description

I would like an explanation provided for the following line in the fs docs (commit):

The callback-based versions of the fs module APIs are preferable over the use of the promise APIs when maximal performance (both in terms of execution time and memory allocation are required).

I could find no info on this. Why is fs's Callback API more performant than Promises API and how big is the difference?

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• I would like to work on this issue and
  submit a pull request.

[aduh95]

Discussion on this subject is in #37583. Closing as duplicate.