rclone can be used for parallel file transfers.
Usage example:
$DEST_HOST: Destination hostname$DEST_USERNAME: Destination username to authenticate with$SOURCE_PATH: Source file/directory to copy from (on local file system)$DEST_PATH: Destination directory to copy torclone copy \
--progress --multi-thread-streams=8 \
--sftp-host $DEST_HOST \
--sftp-user $DEST_USERNAME \
$SOURCE_PATH \
:sftp:$DEST_PATH
Full docs for SFTP available here.