So any compatible radeon HD gpu with crossfire will be slower than the gtx660. How odd
this answers my question! Thank you
An APU like your A8 has a low end on-die GPU along with its CPU. But the only discrete gfx cards that will work in Dual Graphic mode with it, are like-power gfx cards. Two of them is still no match for a powerful discrete card like the GTX 660.