I have a 2011 iMac with the SSD+2 TB HDD option. In the last day I've noticed that my incremental time machine backups take a long time to complete. I'm using an external GoFlex 3TB connected via FireWire. I tried using the drives USB connection, but still experienced that same slow incremental backup times. A backup of 182.9MB would take close to two hours. Also , the process, backupd was show 19.2% CPU usage. I tried disk repair on the drive and even went so far as repartitioning/formatting and then running the Time Machine backup again. All my system and software updates are current. I've also done several shutdown/startups in the process of troubleshooting the issue. The initial backup is extremely quick. It's the following backups that are the issue. Any suggestions to a fix?