Max Speed supported by CoreFTP

[tofus]

Hi,
Is there a maximum speed limit for CoreFTP ?

I am running a CoreFTP server at home (Speed 350Mbps/Down and 20Mbps/Up)
I am trying to upload from a remote office that is on a leased line (300Mbps/Up and 300Mbps/down) to my home server, but no matter what I try, I can never get upload speed above 8 MB/s, Speedtest showed the line is operating at full 300Mbps up and down, and my home broadband speedtest showed 360Mbps/17Mbps so its not a broadband or leased line speed issue.

I altered the buffer from 8192 to 16384 then 32768 but they rarely made a difference, still uploading at 7.6 MBs average which is 3 or 4 times slower than what I should be getting, making transferring backup files over FTP 3-4 times longer, when its a few GBs its fine but most of our backups run into TBs so 3-4 times slower is a real pain instead of hours now its half a day to a day.
What am I missing to improve the upload speed ?

Both the remote and local all on Gigabit LAN and the FTP server does not run anything other than CoreFTP, I didn't even try SFTP because from experience it is slow as hell with our backups over SFTP.
Thanks for any help on this .

[ForumAdmin]

Toggle the "Disable Nagle" option in the domain setup of Core FTP Server. Settings will go into effect on the next server start.

[ForumAdmin]

Setting the send/receive buffer sizes to 8092 should show a significant difference in speed for FTP/SSL/TLS/FTPS

[tofus]

Hi, Apology for the delay.
Only just had a chance to play with SFTP again as I have been using FTP purely because it works and its fast.

Same two sites :
Site 1 = 300Mbps UP/Down (client)
Site 2 = 500Mbps Down/50Mbps UP (Server)

When using FTP transfer from Site 1 to Site 2 , Speed average 15-25/MBs as expected

When using SFTP transfer from Site 1 to Site 2 , Speed is now 2.6MB/s

I have set the buffers on server to 8192 both Send/Receive
Toggled 'Disable Nagle' option but speed is still super slow. WIthout this on, speed is 1.2MB/s

I know SFTP has a lot of overheads because of security, but is there anything else I can do to speed this up ? As I don't really want to use FTP because the lack of security during transfers.

Thanks for any help.