sync command is too resource intensive

[LeZuse]

npm-shrinkwrap sync makes my Mac unusable (100% CPU load) on a larger project.
Repro:

rm -rf node_modules
npm-shrinkwrap sync

Is this the right use case for sync? If not, it should be probably fixed anyway. Will provide more info if needed.

[FelikZ]

Any workarounds? I am using npm install and then npm-shrinkwrap sync, that performs a bit faster for me but not in all projects.