Rsync and/or delta file transfers

[hemicorpectomy]

Referencing sections of a couple of previous posts by Zenju (both at least a couple of years old), I am wondering if there has been any change to this information or the thinking/position about this in the past few years:

"...The method of resuming file transfer that is described in the article requires a server/client architecture. Currently there are no plans to integrate such a thing in FreeFileSync, as this is useful only if synchronizing over a low bandwith connection like the internet...."

"...plans to implement rsync
Currently not, but technically it is possible to implement it after
introducing a file system abstraction layer, which FFS already "almost" has...."

Other comments found by searching indicate the idea that adopting a method for delta file transfers would not be worthwhile for FreeFileSync on a network, as it is apparently nearly as quick to transfer the entire file, since to read and compare two files to discover which blocks are new and need to be transferred takes nearly as long.

My interest was raised in this, after finding that some programs in windows seem to change the date of a video file of several gigabytes, merely by viewing the video. It is not clear that more than a few bytes of the file have changed, if at all, and syncing that file to keep the file structure the same on a backup directory or 2nd computer takes time and bandwidth for no apparent reason. Is there a solution to this?

Also, commercial software called GoodSync apparently implements a server-client solution, and I presume that software is used mostly over networks. So is that a selling point for GoodSync that is really not necessary? Or is it a true advantage of GoodSync?

Thanks,
Michael

[roklobsta]

I agree about differential compression. I used FFS over an ADSL connection and what takes hours might only take minutes sometimes if Microsoft's RDC was used. If both ends support RDC, why not use it?

Here's the developers page.

http://msdn.microsoft.com/en-us/library/aa373254%28v=vs.85%29.aspx