One of the primary goals of the upcoming Composer 2.0 release is decreasing the memory footprint and increasing the performance of common commands. I decided to test out the performance of the second alpha release of Composer 2.0 to see how much real-world change users can expect to see. 

tl;dr: Composer 2.0 will be much faster. Users can expect to see up to a 2x gain in speed in composer create-project commands, up to a 10x gain in composer require commands, and a over a 2x gain in composer update commands. 

I have Composer installed both on Mac OS X as well as automatically via the DDEV web containers that I use for teaching and client work on a day-to-day basis. I ran four tests for three different composer commands (create-project, require, and update) - 2 tests on Mac OS X (Composer 1.10.8 and 2.0-alpha2) and 2 tests in the DDEV web container (Composer 1.10.8 and 2.0-alpha2).

The Composer team has made it super-easy to test out Composer 2.0 using:

composer self-update --preview

To return back to your original version:

composer self-update --rollback

Test methodology

• To mitigate any caching effects, each test was run 3 times consecutively.
• All tests were run on a 13" 2018 MacBook Pro with 16GB RAM, SSD, running Mac OS X Catalina (10.15.5).
• DDEV tests were run with: version 1.14.2, NFS, project type of "Drupal 9", and Docker for Mac 2.3.0.3. 

The results

The graph above displays the average of each test's three runs. The composer require command (using Composer 2.0-alpha2) is slightly faster in the DDEV web container than Mac OS X - this is a surprising result, and one that I can't explain.

composer create-project drupal/recommended-project

• Mac OS X Composer 1.10.8: 40.4, 12.9, 11.7 seconds
• Mac OS X Composer 2.0-alpha2: 9.0, 10.8, 10.1 seconds
• DDEV Composer 1.10.8: 116.9, 81.4, 92.0 seconds
• DDEV Composer 2.0-alpha2: 66.8, 63.3, 52.8 seconds

composer require drupal/pathauto:1.7.0

• Mac OS X Composer 1.10.8: 63.2, 45.5, 19.8 seconds
• Mac OS X Composer 2.0-alpha2: 5.3, 3.2, 3.7 seconds
• DDEV Composer 1.10.8: 79.9, 56.7, 29.8 seconds
• DDEV Composer 2.0-alpha2: 3.3, 2.8, 3.0 seconds

composer update drupal/pathauto --with-dependencies

• Mac OS X Composer 1.10.8: 36.8, 28.5, 41.4 seconds
• Mac OS X Composer 2.0-alpha2: 14.6, 13.2, 12.8 seconds
• DDEV Composer 1.10.8: 51.1, 24.7, 44.8 seconds
• DDEV Composer 2.0-alpha2: 16.1, 16.0, 15.6 seconds

More information

For additional details about the upcoming Composer 2.0 release, see this slideshow by Nils Adermann (co-creator of Composer) and this article on PHP.Watch for additional details.