So I got dual card setup, have everything configured and ready to start mining.

When selecting devices, I can either select device 0 or device 1, so my question is, if I set up job 1 and select device 0-0 and then set up another job and select device 0-1.  Are the gpus working independently? Or will they be hashing at the same block?

If they are independent, can I combine their processing power on the same block without xfire?