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FTP upload speed

Feb 01 '17 at 10:30

I am using Delphi with FTP2 for several years successfully. One of my customer has Download speed of 8MBPS and Upload speed of 500KBPS. Uploading a file via my application that uses your FTP uses the 500KBPS speed, whereas uploading the file via FileZilla uploads at 8MBPS speed. Please advice ?

Regards Allan Fernandes


For any socket sending performance issues, regardless of whether it's FTP, HTTP, Socket, etc., here are my suggestions:

1) Greatly increase the value of the object's SoSndBuf property. You might want to get the property value after the initial connection to see the system default value. Then increase it by a factor of 4, or it try using a value computed according to socket buffer size = 2* bandwidth * delay (see section 4.1 here:

2) If the class has a TcpNoDelay property, compare with values set to true/false.

3) Make sure verbose logging (the VerboseLogging property) is false/0.

4) Make sure you're not running a debug build, or linking with the debug build of the Chilkat lib. Make sure you're using the fully optimized release build.

5) If using an old version of Chilkat, update to the latest version..