I should clarify this. The 100 MB window in SnowFS is currently unrelated to compression as it is only used to compare if a block changed. Each block gets a hash. This is a fallback used for some file formats where the mtime timestamp cannot be trusted. Some files have a change in the first block e.g. 100 MB and that is faster to compare than an entire 8GB file. But this window size is dynamic and can be changed and used for compression in the future
Ahh this is my bad. For some reason I assumed the blocks were part of the storage scheme, but I see they only are used to compute hash, and that the whole file is added to zip. Sorry for the misunderstanding!