Sorry for my English, and I don't no if i can post this here...
Original post in French :
When i download a file beetween 2 computers (Fedora16, KDE with Dolphin), the download speed (~10Mio/s) is faster than the upload speed (~2Mio/s).
I post here because i have this answer from KDE :
------ Comment #1 From Andreas Schneider 2011-12-01 10:19:10 ------
Thanks for taking the time to report this bug.
kio//sftp is using libssh. libssh provides an async api for downloads but not
for uploads. Please request async upload support upstream.