I have a samsung laptop with a radeon 8700m card as well as intel hd graphics.
I have had a mountain of issues with this. Applications and games often only want to detect the intel card. I have tried updating the graphics card multiple times, but the amd site cannot even detect a compatible card, the samsung software update utility allowed me to update, but even the catalyst control center only allows me to see the intel card.
The odd thing is, I can still play some games great, most recently was bioshock infinite at medium settings and 1080 with no lag except a slight second when traveling between areas.
Deus Ex though has randomly run perfect some runs and then crappy the next time I play. Alan Wake is impossible to get running on even the lowest settings above 5-10fps, and resident evil 6 I immediately get a black screen and the game stops responding.
I feel that most of these issues have to do with some combination of the graphics and windows 8 personally. I had an older samsung laptop with windows 7 and a less powerful gpu and could run every one of those games listed med-high settings just fine.
sorry I cannot help you yet, but I wanted to share the similar issues I have had trying to figure out who to get my games running properly and consistently. I will be sure to share my progress if I manage to make any.