Latest version of Lightroom (5.7) spools what seems like endless disk requests to create XMP files resulting in system freeze on import. Anyone else having this problem? I have never had this before.
Open Lightroom 'Catalog Settings' Metadata panel and make sure that 'Automatically write changes into XMP' is unchecked.
When above option is active Lr will write each and every change to a photo back into an XMP file. This includes any metadata you apply during import.