According to PCWorld , AMD Trinity APUs A10-5800K + AMD Radeon HD 6670 =AMD Radeon HD 7850 (In GPU performance). Is it true ? http://www.pcworld.com/article/2010666/amd-announces-trinity-apus-superb-graphics-improved-cpu.htmlMy question is why AMD Trinity APUs A10-5800K can not crossfire ATI 7XXX or higher than 6670 ?