Well, title says it all. Now I have to backup my important files which are roughly 2GB (only 3 truecrypt containers) and it will take me ~10 times slower than my actual upload speed to the server.
Regards~
Do you mean you want Opus to transfer the files using three connections, having them join up at the other end? As far as I know that is impossible using FTP when uploading.
It is possible when downloading files to your local computer, since it only needs special work to be done on the client side, but when uploading files the FTP server at the other end has to know to join everything together.
Which direction did you have in mind?
Or do you just mean you want to split the files into a few parts and then manually upload/download each part in parallel, so that if you need them again you can grab the parts and join them? If so you can use Opus's split and join commands (or something like RAR's split-archive support). Too much work if you're doing a lot of files, but for just a few not so bad.
I had in mind upload because before making DO my default FTP client I used CuteFTP which have this feature. But never really used it for the small uploads I had these days. Now after posting here I decided to install it just for this task but received a message that this server doesn't support multi-threaded upload. So you are particularly right - the server needs to be configured to provide this.
Thanks for the idea of splitting files. I don't know why it didn't come to my mind earlier.
I discard my feature request for the probable limited usage and in favour of something more anticipated like copy queuing and so on.
Okay. 
I didn't realise some FTP servers had such a feature. I wonder how many servers support it and if there's one standard way to do it or lots of different ones?
Hmm, I really don't know. I accepted by default that if my ftp client has it there should be a corresponding possibility in servers too. May be this is not the case.
Now I'm starting to think that it's impossible or you wouldn't ask me like that 
I don't know if it's possible or not. I don't know the FTP protocol/specifications very deeply myself.