Afterburner works no probs with CCC intalled, if you are going to OC your 5850 with a slight OC use CCC, my 5870 is OC to 875/1250 [64'c-fanspeed 28%] using CCC it also tests your OC. Have OC my 5870 upto 900/1275 stable with no voltage increase with CCC, forgot what temps and fan speed were but ran ok.