old (leveldb) vs new (bolt):
jb@syno:~/src/github.com/syncthing/syncthing/internal/db (leveldb) $ go test -bench . -benchmem > ~/a
jb@syno:~/src/github.com/syncthing/syncthing/internal/db (leveldb) $ git checkout boltv2
Switched to branch 'boltv2'
jb@syno:~/src/github.com/syncthing/syncthing/internal/db (boltv2) $ go test -bench . -benchmem > ~/b
jb@syno:~/src/github.com/syncthing/syncthing/internal/db (boltv2) $ benchcmp ~/a ~/b
benchmark old ns/op new ns/op delta
Benchmark10kReplace 68852446 24119329 -64.97%