I know I"m a little late to the party, but I would like to share with the people who are testing Fedora a tip to speed up dnf. Edit as root the file located in /etc/dnf/dnf.conf and add the following line:
and save the file. dnf should fetch packages much faster now that downloading occurs in parallel. dnf’s grabbing of metadata is still slow, but I hear they plan to speed that up in future releases of Fedora.