Shredded Storage -Another new feature in SharePoint 2013. It reduces the amount of the space required for document storage for SharePoint Document libraries.
How it works?
Whenever a document is modified, it stores only incremental changes not the entire document. It is enabled by default . At Web application level you can enable by setting FileOperationSettings property of the Web Service member of the web application.
Powershell command to disable Shredded storage
$w.WebService.FileWriteChunkSize = 1073741824
$w.webservice.update()
There are lot of performance implications with shredded storage if not implemented properly.