From Fedora Project Wiki

ThorstenLeemhuis, 20081122: Would be nice if anaconda could format in background with a low priority, because that really disturbs and interrupts the whole first part of the install: You start the install, you do the partitioning <wait a long time for formating to finish>; then you do two or three mouseclicks again <wait a long time for installing packages>. Getting rid of the "<wait a long time for formating to finish>" part would be a huge benefit.