Take advantage of HPN-SSH
New developments take place regarding threaded-ssh, this might be a good idea to implement in winSCP in order to fix the speed issues when using AES or other CPU-intensive ciphers.
https://www.psc.edu/hpn-ssh-home/hpn-ssh-faq/
https://www.psc.edu/hpn-ssh-home/hpn-ssh-faq/