[alexbilbie]

Are you committing the composer.lock file in your projects? Likewise you should try and use as close to absolute version numbers as possible in your composer.json `requires` sections.

I used did a quick test (having run `composer clearcache` each time) on one of my projects:

Without composer.lock: Memory usage: 75.96MB (peak: 87.5MB), time: 38.54s

With composer.lock: Memory usage: 7.47MB (peak: 8.99MB), time: 28.6s

[riquito]

I do, I also have just absolute version numbers. I'm not the only one with such problems

https://github.com/composer/composer/issues/1898