Read ahead over SFTP: one connection with 32 requests in flight by default, more with restore_sftp_connections; a Storage Box gets slower with parallel readers

CHANGELOG.md

@@ -10,11 +10,11 @@ instead carried by the app description, the git tag, the release, and this file.
 ## [Unreleased]
 
 ### Changed
-- A full restore over SFTP reads the packs ahead on 4 connections of its own, many requests in
-  flight on each, into temporary files in the restore folder. From a Hetzner Storage Box to a
-  server in Canada (122 ms) packs now come in at about 7.6 MiB/s instead of 2.8; on a test line
-  with 120 ms and some packet loss, a 1.6 GiB restore went from 5.1 to 17.8 MiB/s. A part that
-  cannot be read this way is read as before. Restores from other locations work as before.
+- A full restore over SFTP reads the packs ahead on a connection of its own, 32 requests in
+  flight, into temporary files in the restore folder. From a Hetzner Storage Box to a server in
+  Canada (122 ms) packs now come in at about 14 MiB/s instead of 2.8. More connections can be set
+  with `restore_sftp_connections` (README). A part that cannot be read this way is read as
+  before. Restores from other locations work as before.
 
 ### Fixed
 - After a full restore stopped halfway, running it again with `--force` was refused when the