I have just added an explanation to documentation chapter about transfer modes.

BTW, I do not think I'll ever resolve this, because the obsolete SCP protocol is not worth it.

Hello,
I tried to transfer files from windows2000 to linux in text mode.
:shock: WinScp was unable to copy a file with size of 217MB: I had to kill that transfer after 16 hrs (!).

:idea: Problem of winscp is that it tries to allocate too much memory (see page faults and VMem fields in windows's task manager). Probably it tries to convert the whole ascii file in memory before starting the transfer instead of doing conversion just-in-time: i.e. pipeline ascii conversion process to transfer process.

Anyway, Windows's ftp client transfered that file in 5 minutes in ascii mode- so I transfered the file this way: ftp in ascii to another node, then back by ftp in binary mode and finally by winscp in binary mode to the target computer.

It would be nice to fix this performance leak.
Best Regards, Andrej