Description of problem: On a 100Mbps network, I can transfer files with an average throughput of 11.1 MB/s with sftp get command in Konsole. Transferring the exact files using Dolphin and kio_sftp gives an average throughput of only 1.2 MB/s. Version-Release number of selected component (if applicable): unknown How reproducible: Always Steps to Reproduce: 0.a. Setup a gigabit network with at least two machines and a multiGB file to download on one side. 0.b. Set up ssh access on machine 2 1. On machine1 open Dolphin 2. Click on the "address" bar. The bar becomes editable 3. enter "sftp://<user>@<ip_of_machine2>:/home/<user>" 4. Enter password when prompted for one 5. After directory loads, "copy"(Ctrl-C) a large local, and "paste" (Ctrl-V) it in the Dolphin window. This starts the transfer. 6. Use the "Network Management" widget to observe transfer speed 7. Try to copy the same or a similar file with scp: $ scp large.file <user>@<ip_of_machine2>:/home/<user>/ 8 Observe the transfer speed either by watching scp output, or using the "Network Management" widget. Actual results: kio_sftp: about 1.2 MiB/s average throughput scp: about 11.1 MiB/s average throughput Expected results: Same throughput using both scp and kio_sftp, and same cpu usage. Additional info: I transferred one contiguous 65 GiB file. Speeds remain constant in both escenarios. Dolphin scenario almost 2 days downloading some 215GB. I read someplace in bugs.kde.org a similar problem solved by increassing some buffer size for samba kio slave. I copied this bug description from https://bugzilla.redhat.com/show_bug.cgi?id=985113 replacing statistics with my own data.
Please open a bug at: https://bugs.libssh.org and ask for a complete async sftp API.
I did open the bug. Is there anything that can be done with buffer sizes or is it a totally unrelated problem as I guess?
It isn't related to the buffer size. The API is blocking ...