Hello! In first, sorry for my english. I pay attention to this thread because on my mobo, i've only one pcie 16x & 3 Pcie 1x but i've 2 R7 250. On this type of graphic card, there's no crossfire connector. After reading this thread, i try the catalyst 13.4 but i modify them( .ini et .msi), the R7 or HD8670 came 6 months later. The 13.4 finally wok fine. I try ADL_sample. I pass 2 days to find the DLL to make it work but no chance in my case, the 2 cards are in crossfire= -1. So, i'm searching for a trick to make functional the crossfire with this 2 cards, perhaps it's not possible with my mobo. Oh... Sorry, i'm under 7 x64 sp1. I've tested under ubuntu 13.10 but 2 problems: I'm not expert in Linux and the glrx drivers doesn't recognize the R7. I've got another fool project: I've an operational motherboard of HP 9212ea, mobo functional but the gpu has been removed, so, i've the 16x lane to make something interesting if the mobo wants. i've a 4870x2 but after testing in 1x, this type of card is very bandwith dependant. Thanks to read (and help me if you want)