We do transmit "changes" to large files in 10 MByte chunks. In other words, if 1 byte changes in a 50 MByte file it SHOULD only transmit one single 10 MByte ch

We do transmit "changes" to large files in 10 MByte chunks. In other words, if 1 byte changes in a 50 MByte file it SHOULD only transmit one single 10 MByte chunk. The absolute worst case for Backblaze is if you insert a single byte at the start of a large file. This "shifts" the entire file along by the one byte, effectively changing every single 10 MByte chunk. The BEST case is if you append a single byte to a large file, because the final chunk then is probably less than 10 MBytes. I actually thought we would be working on that area quite a bit over the years but it kind of worked well enough. :-) Most people don't edit large files, with the exception of Outlook.pst files, we see those appear as bandwidth burners.