One of the answers to this question suggested using Geth's
--fast flag to help quickly synchronise the block data.
How does the flag work, and how does using it speed up the synchronisation? Are we syncing less data, or are we in some way performing fewer checks on its integrity or source?
As of Geth version 1.6.0, the
--fast flag has become
--fast is also still usable for now).
There's a lot of detail on this PR on github. Here's a quote: