Rebex SFTP slow, providing only 500 KB/s speed when uploading

Question

Hello Team,

I am using rebex sftp using C# for file transfer (Upload/Putfile). when I check speed it only giving 500 kb/s. I have used below setting:

   sftp.Settings.UseLargeBuffers = true;
   sftp.Settings.SshParameters.Compression = true;
   sftp.Settings.UploadBufferSize = 60 * 1024;
   sftp.Settings.UploadQueueLength = 8;

but not getting any success. I am expecting transfer rate more 5 mb/s. So Can you please help me to increase transfer rate.

Thanks,
VJ

Answer 1

Please create a communication log of sftp.Connect (created using https://www.rebex.net/kb/logging/) and mail it to support@rebex.net - this should give us some idea about the server and ciphers in use.

We would also like to know:
- What speeds do you get if you disable compression?
- How fast is the connection between the client and the server?
- What kind of speed can you achieve using a third-party SFTP client such as WinSCP or FileZilla when uploading to the same server from the same machine?
- As for the speeds, are you actually referring to kilo‎bits or kilo‎bytes?

In general, the following settings usually result in decent speeds:

sftp.Settings.UseLargeBuffers = true;
sftp.Settings.SshParameters.Compression = false; // only enable compression when transferring highly-compressible files
sftp.Settings.UploadBufferSize = 48 * 1024; // 48 KB is maximum allowed value here 
sftp.Settings.UploadQueueLength = 128;
sftp.Settings.DownloadBufferSize = 28 * 1024; // 28 KB seems to result in best transfer speeds
sftp.Settings.DownloadQueueLength = 128;

(Please note that all of these have to be set before calling the Connect method.)