Internet Direct (Indy) Version 9.0.1 Beta
TIdTCPConnection.SendBufferSize
Indicates the maximum buffer size to use for writing to the connection.

property SendBufferSize: Integer;
Description
SendBufferSize is an Integer property that indicates the maximum number of bytes that can be allocated when writing data to the connection. The default value for SendBufferSize is 32768.

SendBufferSize is used in WriteStream to determine if the number of "chunks" needed to Write the TStream contents. When the stream is larger that SendBufferSize, multiple "chunks" will be used.