AIX

     -R num_requests               Specifies  how  many  requests
                                   can  be outstanding at any one
                                   time.  Increasing   this   can
                                   slightly improve file transfer
                                   speed  but  increases   memory
                                   usage.  The default is 16 out-
                                   standing requests.

 
 
     -b batchfile                  Batch mode reads a  series  of
                                   commands  from an input batch-
                                   file instead of  stdin.  Since
                                   it  lacks user interaction, it
                                   should be used in  conjunction
                                   with non-interactive authenti-
                                   cation. sftp aborts if any  of
                                   the  following  commands fail:
                                   get, rm, and lmkdir.