@Willi: Please start a new thread and post session log files both from WinSCP and FileZilla (both latest versions, both running on the same machine).

Hi, I am new here, but I used WinSCP for many years. Since some months, I noted that the download of long files is very slow during the first half of the transfer. Typically, the transfer starts with somewhat more than 1 MBytes/s, but slows down to about 0.3 MBytes/s hereafter. When about 50% of the file is transferred, the speed may accelerate instantly to much more than 10 MBytes/s, so, the second half of the transfer is much much faster.

Today, I tested FileZilla and was really astonished to note a continuous and stable transfer speed of about 70 MBytes/s. Two .mp4 files, 33 GBytes in total, were downloaded in less than 8 minutes!. I tested a much shorter .mp4 with WinSCP hereafter but stopped when I noted again the slow transfer rate mentioned above.

Is there any reason for this boring behaviour of WinSCP?

I use SFTP.

I'm not sure I understand, I have trouble with English, I'm a French speaker, but in the descriptions I read

That with several connections it does not slow down the transfer. I have checked "Use multiple connections for a single transfer".
But when I copy a folder to my PC, it says in progress "Display content..." it's long no way to make it instant without calculation or other?

See https://winscp.net/eng/docs/ui_transfer_custom#calculate

Note that when using multiple connections, the calculation does not add time to a transfer, as directories are not listed again for the transfer itself.

Thank you, indeed using this is very fast, however, is there a way not to do the calculation of the size before which takes a lot of time?

See https://winscp.net/eng/docs/faq_slow#transfer_queue

Hello,

Sorry for the delay in answering but I was on FileZilla !

However, nothing to do your software is better on all the other points that the file transfer!

For example :
With FileZilla I transfer a Prestashop site it takes me +-5 Min

With WinSCP I transfer the same site, on the same server, it takes +- 30 min...

I don't touch anything in the settings :( I don't understand why it's so slow with winscp! one file transfers fast... but as soon as there are many small files it's slow.

I guess it's because FileZilla connects several times while winscp does not?

Translated with www.DeepL.com/Translator (free version)

What does it mean "it loads in loop"? Can you post a session log file (and maybe some screenshot[s]) documenting the problem?

Hello, with my WinSCP I have a configuration problem, I would like it to be as fast as FileZilla for batch file transfer.

I often have hundreds of thousands of files of some MO to download, but it is just impossible with WinSCP.

In default, it takes about 30 min for 100 mb, if I activate the background, it loads in loop without downloading the files (I didn't let it run for long, but I would like it to be instantaneous, you ask for the copy, it copies directly, without having to calculate anything.

Is this possible?