I'm mining right now with a GTX 880m, Marlin miner, siamining pool and around 420 MH/s. I don't think it's profitable in terms of electricity costs anymore, but right now it's just for fun and with the prospect of siacoin going up at some point. If somebody wants to try, this guy here has a good tutorial to start: https://mtlynch.io/windows-sia-mining/ (he really thought of everything, I had it running in no time)