Allway Sync is a file synchronization program which will enable you to syncronize your data between PC’s, Laptops, External Hard Drives, Servers, Online Data Storage and much more.
I use it to backup images contained in multiple folders on 2 of the 4 drives in my computer and these are backed-up to x3 (2TB) external WD hard drives via USB 3.0. The software allows you to synchronize your files automatically as changes take place or at times specified by you or at any time you want. The way in which you backup your data is very much down to you with multiple choices available.
This software not only saves me time but makes sure all my chosen files are backed-up whereas in the past using manual backup I have made mistakes and not backed-up the odd image.
My only negative comment (please bear in mind I am far from an expert in many areas of computing) is the instructions for setting up the interface for me were not that easy to follow. Fortunately I have a friend who also uses the program and he set it up for me in about 5 minutes.
Like many hard drive manufacturers my x3 WD external hard drives all came with backup software included but this only allows you to backup to 1 external drive with many other limitations.
For less than $20 Allway Sync gives you reliable backup software that works.