In eyefinity, no. This is because the CPU is doing the same amount of work (the AI isn't any more demanding since its not tied to resolution) but the gpus are working harder because of the higher res.
Just because you run a super high resolution doesn't mean a game that likes more cycles, or more threads is going to work out fine and not care if you have a weak processor.. It doesn't work like that.
Not only does the game need to be powered, but 2 GPUs need information processed and sent out as quickly as possible. Might work fine on older games, but the x2's are just not very good anymore.
OP I would try to get a Quad ASAP if you intend on gaming, let alone going crossfire. Most games now recommend a quad/4threads and your x2 simply can't run them at an fps that makes crossfire worth it.