lftp mirror slow

many files in directory that shall be mirrored

Request: MDTM $filename
Response 213 20170215171525

lftp mirror slow:

Getting files information (2%) [Waiting for response...]

reason: lftp fetches dates of all files first, one request for each file.

ignore date:

$ lftp -c "open ftp://user:pass@host; mirror --ignore-time --parallel=10 foldername/ ."