With your setup you can choose between two encoders: x264 and intel quicksync. x264 uses only the cpu and quicksync uses cpu and also the integrated intel graphics for acceleration. quicksync therefor gives you the best performance, but if you need the gpu power to render a game, that game will likly be unplayable. I am soory for you, but this hardwareconfig isnt really good for streaming....
Dual Core prozessors arent good at streaming :(
As i said, the only thing you can try is using the Intel quicksync encoder in combination with the cbr setting and not setting a high bitrate. That is all i can think of, but maybe there are better settings for you. I only work with high end hardware, so i am not that good with giving advice to people with weaker hardware...
