Very slow transmission speed FFS 12.3

[lingyang]

Got a very slow transmission speed on FFS 12.3 donation edition.
Transfer a 12GB file with only 1 channel 100MB/s
Transfer a 12GB file with 10 channels 50MB/s

Transfer with Filezilla 10 channels 400MB/s

All transfer protocols use sftp everything else is the same. Any explanation for that? Seems too much computation is going on in the background which makes the transmission slow. IS there any chance to make this program run faster? Maybe use some compiler optimization or drastically simplify the background task. I mean Filezilla can do it, why not you, should be no Rocket science, right?
Amazing fact: runs even slower if you add more channels, hey man....really?

[Plerry]

Likely you have left "fail-safe file copy" checkmarked (in FFS GUI / Tools / Options), as recommended.
This creates an overhead.
Even more so, when you would have set the VerifyCopiedFiles flag to True.

[lingyang]

No, neither failsafefilecoppy is on nor VerifyCopiedFiles. It is just so slow now. I remember that earlier versions did not have this problem. I nearly tried all settings variations back and forth. Uninstall/reinstall, fresh setup, nothing helps.

Filezilla is just as fast as my network allows.
FFS is so terribly slow now, what is going on?

Same connection, same files, same hardware

[xCSxXenon]

Does a previous version work as expected?

[lingyang]

I got this impression, that previous versions were faster so I just noticed this degradation recently with the newer versions, actually after I donated. I dont say there is a correlation.

[xCSxXenon]

Install a previous version and test

[lingyang]

Version 9.8 still runs at higher speed. That is still slower than Filezilla. 9.8 can achieve 300MB/s, when Filezilla can make a full 400MB/s. That is why I did not recognize it earlier. But would you agree that a 100 or even a 50 is too slow? Hope that helps.

My machine is a slow outdated Intel core I7 -4790K with a 2TB SSD. Shouldnt this software also run sufficiently on older machines? Why Filezilla can?

What I see, is that even I have 32GB Ram, nothing of it is used as cache while Filezilla is using at least 8GB of it. Hope that helps either.

[lingyang]

I donated, because I hoped that more channels could speed it up. Now I have to see that it even slows down everything. Kind of weird also.

[lingyang]

Seems everything is programmed in VBA and not in C++ if you know what I mean.

[xCSxXenon]

Yeah, that is a significant slowdown... What happens if you disable any AntiVirus programs?
More channels only helps in specific environments as documented

[lingyang]

The same

[xCSxXenon]

What if you perform a manual transfer by 'copy and paste' in File Explorer?

[lingyang]

File explorer? Network?