M18x R2, GPU questions

Hi,

i have an Alienware M18x R2 with one GPU. I have three question, where i did not found any answered till now.

May be, some one can help me.

1. I have a  GTX 640. it works, but I do not see Optimus. Is there a special driver needed, that I get Optimus to function (to save battery)

2. On some videos for repairing this computer, i see a controller card near by the wireless controller. In my computer, this is empty. Do anyone know, for what use this controller is ?

3. On repair manual of Dell is shown, that the place for primary graphic card is left side and secondary graphic card should be on right side. At my computer (i have only one  graphic card), the  graphic card is on right side.Is this wrong or doesn't it matter, where the  graphic card is.

Best Regards