Seriously, there is no way that 17GB or more of data has changed on my iMac within the hour that the last Time Machine Backup was completed. This was never the case under Mavericks. And yet here is Yosemite, backing up multiple gigabytes of data every time a backup is initiated. Over and over again. And it's SLOOOOW. Sometimes taking well over an hour to complete. Is there any way to find out what exactly Time Machine is finding that's unique, and backing up every time? I have less than 300GB on my local storage, and my 4TB Time Machine drive is starting to fill up all of a sudden.