The 6 "cores" of the 6100 are actual 3 "bulldozer modules", or pairs, similar but not quite the same as traditional pre-bulldozer cores (i.e. phenom, athlon) or intel. In some applications they perform as advertised, in this case 6, others they don't, in this case 3. As for the turbo, it is supposed to be an "automatic overclock" when under load, just like you GPU idling at a lower clock rate until needed.
While a 680 is definately more powerful than a 7850, it's not a huge upgrade and may not be worth the money at this point. And with that cpu you might not notice a real world difference except at very high resolutions on a couple games.
edit: Sorry if this does translate well to swedish, but than you for making a valid attemp to communicate in English