The CF app chunks files up into software busmessages. cFE has a limit on SB packet size of 32K. Figure out the acceptable rate at which you can send packets, multiply it by 32K, and that's about the limit. (There's a little overhead with packet headers.)

The theoritical limit is pretty high, but keep in mind system bottlenecks. Maybe it's file write speed. Maybe you have hardware downstream which has a smaller packet size limit. Maybe your ground system can't handle 1000 packets/second.

CFS has a CF application that follows the CCSDS file delivery protocol (CFDP) version 5. As for speed, I would think it depends on your system and the configuration.