Out of curiosity, are you running an Nvidia card? (This may apply to radeons as well, but I don't have any experience)... For the NVidia drivers at least, there

Out of curiosity, are you running an Nvidia card? (This may apply to radeons as well, but I don't have any experience)... For the NVidia drivers at least, there is an option to select which graphics card to use on a per-application basis. Normally the drivers default to auto-selecting what it thinks is best, but you can override that in cases like this.