I upgraded from a 5850m to a 7970m and so i compared the 5850m x-bracket to the 7970m. My experience is that the official x-bracket that comes with the 7970m has scew holes that are too long. You would need to file the screw holes down to about 3mm. This is so that the heatsink applies sufficient pressure to the GPU. Please also note that the 7970m at stock voltage seems to run really hot in an m15x. Hence, i am in the process of trying to undervolt. But, i am really afraid to flash a new vbios for fear of bricking the card.