The file upload and down road hour transport speed are slow too with sftp.
The existing ftp transmission is not a problem.
But the transmission at the time of 13M criterion file transfer time 1 minutes become 30 second degree disturbance with sftp.
This compares and different SFTP Client (FileZilla, winSCP etc.) time of 6~7 second degree and is slow too.

When solves a problem does to do how?
They are libssh2 problems?
Reply entrusting it gives.

px) Memory leak problems solved in the last time.
    Billd environment of the other library field including curl.lib (MFC static library) with the loach gives the problem was solved.
    Reply thanks gives.