The Transfer Speed Limiter is shown in the program status bar. By default, speed limiter is not in use, and it shows:
Speed limit: No limit
The speed limiter sets a maximum number of bytes transferred per second, and therefore it controls the amount of network bandwidth 3D-FTP uses. Normally you can leave this limiter to its "No limit" default setting. But sometimes, in the middle of the large FTP transfer, you may want to browse the internet with web browser, or need to perform other actions that requires internet connection bandwidth. In those cases, you simply drag the speed limiter scroller to the limit you want to use, like setting:
Speed limit: 200 KB/s
means that 3D-FTP uses maximum of 200 kilobytes per second for file transfers, and rest of the bandwidth is free for other uses. This way file transfer can continue in the background, but it does not consume all the available bandwidth.
NOTE! Speed limiter remembers its setting over sessions, and restores the set limit on the next program startup.