Background: I can normally upload at 2 mbps (megabit per second) which translates to approx 250 KBps (kilobytes per second). I have tested this speed using various speed tests, other FTP servers and AIM file transfer so I know it's accurate. I'm using 1.07 of the Core FTP Mini Server (msftpsrvr.exe). On the client side I am using 1.3c of the CoreFTP LE. I am using a nonstandard port (not 22) and that port is being forwarded by my router.
Problem: My upload speed is capped at approx 75-80 KBps. I have tried various client hosts to ensure that it's not the client downstream rate that is the bottleneck. It is definitely the mini FTP server that is causing the problem. Now I understand of course that encryption and authentication adds overhead and that the speed will probably not reach the max upload speed of my connection due to that overhead, but a 300% drop in speed seems a tad much. There are no options that I can find for compression or changing algorithm information or anything like that. Any ideas on what might be causing this slow down?