[I repeat here my post from a couple of weeks ago for those recently flaming about slow backups].
I recently installed iDrive on Windows 10 computer to replace Carbonite, then reinstalled an updated version. The incremental backup with the current updated version was then taking much too long, with an estimated completion time of approximately three hours according to the progress report at the bottom of the iDrive window.
I launched the windows Task Manager and noticed that my Norton 360 antivirus was consuming more CPU time and disk reads than the iDrive Service. I guessed that Norton was scanning each of the 137,000+ files in my target backup set, each of whose properties iDrive was checking to see if the file had changed since the previous backup.
I then launched the Norton Security Suite software and turned OFF its Antivirus Real-Time Auto Protect for 15 minutes.
The result was that the iDrive incremental backup dramatically sped up and completed in a few minutes instead of the three hours it had estimated earlier.
So...try turning off your antivirus scanning software, like I did, to see if it speeds up your backup, like it did for me.
I'll report this separately as a bug both to iDrive and to Symantec/Norton.