i've tried going to bios then peripherals>gfx options>internal graphix = force..

still, no crossfire option.. what should i do? someone help me..

BTW.. Im using the 12.10 driver, 

My specs is:

Proccessor: a10-5800k 3.8ghz

gpxcard: Sapphire HD 6670 1gb gddr5 128bit

PSU: corsair tx 650watts

mobo: gigabyte GA-F2A75M-D3H FM2

ram: 4gb team elite ddr3 1333mhz

In desktop right click>AMD VISION Engine CC>Performance>Dual Graphics>Enable

Also did you plug in the 6670 and plugin the vga/dvi/hdmi cable from it to your display

thx for the reply sir, but my problem is.. i dont see the dual graphics option in CCC.. ive already plugged in the cable in the graphics card.. but still it doesnt show.. what seems to be the problem for that?

You need to make a stop into BIOS. Find the tab for North Bridge settings, force the IGD, and enable surround view.

And, there seems to be a lot of people saying to plug into the dedicated card, or else it won't be used. Plug into your motherboard's output using the APU. Using the APU (in my experience) has yielded better performance than using the dedicated output. Both cards are being used.
In my tests:
IGD output alone WEI = 6.7 for graphics and gaming graphics
6670 output alone WEI = 7.0 for graphics and gaming graphics
IGD + 6670 using IGD output WEI = 7.1 for graphics and gaming graphics
IGD + 6670 using 6670 output WEI = 7.1 for graphics and 7.0 for gaming graphics

Using a slew of games and open hardware monitor watching the core clocks and memory clocks of the R6670, I can see that even when gaming off the APU output, the clocks of the R6670 go up and the dedicated GPU is being used.

AMD A8-5600K
MSI R6670 1gb GDDR5
BioStar Hi-Fi A85W
4x4gb Gskill Ripjaw X
Corsair TX650
Corsair 400r
Cooler Master s524 HSF

thanks for the reply sevenfacedsin,  i have search everywhere in my bios setup looking for the surround view. but i cant find it in my bios.. its really frustrating for me.. T_T