A Node.JS process runs almost completely on a single processing core, because of this building scalable servers requires special care. With the ability to write native extensions and a robust set of APIs for managing ...
https://hacks.mozilla.org/2012/11/fully-loaded-node-a-node-js-holiday-season-part-2/
https://hacks.mozilla.org/2012/11/fully-loaded-node-a-node-js-holiday-season-part-2/