max download speed

i have a question about the max. download speed. a download with winscp has a rate of 450 kb/s, but i have a max download of 6600kbit/s (~800kb/s). why can't winscp download with 700kb/s oder more?

sorry about my very bad english, i hope anyone can understand my problem.

Yours sincerely Bootscreen

Due to nature of the protocols (SSH, SFTP) it is not always possible to utilise the whole bandwidth.