how to use only a single gfx card which is setup in xfire?

[ramesh4388]

hi guys.....i'm planning to buy alienware m18x laptop from usa .....

1. i'm going for the dual 7970m xfire combo.
2. now since i use the laptop mostly away from a power source i'm in a need to save the batery.
3. my questions are:
a) how to use only a single gfx card which is setup in xfire to save battery?
b) can i switch off power to the graphics altogether and just use hd4000 with the help of any software which can revert back as and when required?
c) how to underclock the gfx card and will it save the battery?
4. thank you

[sam]

a) should be possible from AMD Catalyst Center > Gaming or Performance. It should have option to turn Xfire on or OFF.
b) same as above. AMD CCC. I think if you assign power saving to any application it'll use HD4000 when on battery. As it can be done in laptop with single GPU so should be possible in dual GPU laptops too.
c) won't. underclocking will only cause lower performance and these GPU are really power hungry so won't increase battery life by more than a few minutes.