Myths and Facts about Delta Sync – Why Delta Sync doesn’t matter ?

What is Delta  Sync?

Delta (Differential) sync is a type of synchronization technology that will only synchronize parts of a file that have been updated or changed. The general claim is that delta sync technology will help to save time and bandwidth by just synchronizing the changed parts instead of the whole file. For instance, let us say you have a 10MB file and you are changing just 1 bit, instead of synchronizing the whole 10MB file it will only  sync the changed bit. At first glance, it seems to provide huge benefits for large files. But it is a myth and a hyperbole by vendors who espouse this technology for marketing purposes.

The Facts

The fact is that for most of the modern files types (especially the large ones) delta sync won’t help at all. The simple reason is that majority of the widely used modern file types (pdf, jpeg, png, .docx, pptx, docx, .mp3, .mp4 and many others) are compressed . Unfortunately, compression negates any benefit from delta sync. When a file is stored compressed, in the process of saving the file, the file is run through a special process that finds duplicate data and removes it.  Even if you change a bit in a compressed file format,  it will change the entire file.  Also , you will be hard pressed to find a modern file format  that is not compressed especially the large ones. For instance, let us say you are editing an image file (.jpeg) you will not see any difference between a regular sync and delta sync. The reason is  that .jpeg is a compressed file format like many other image formats. The same thing applies to your video files and office file formats.

Where will Delta Sync Help?

Delta Sync will help in scenarios in where large files are stored uncompressed. The most typical case is log files for system administrators. For instance, web server access logs can often get quite big (MBs to GB).  This is an ideal case for delta sync. But again how often do you sync a log files using your Enterprise File Sharing and Sync solution.

Next time when you see delta sync marketed about as a way to save bandwidth and time, please take those claims with a grain of salt. The real criteria that one must consider for evaluation are  the security of the Enterprise File Share and Sync (EFSS) system, ROI, custom branding, user experience and fine grained sharing controls. Delta Sync should not be a criterion for evaluating an EFSS solution. It simply doesn’t matter.