really. 7950 works just fine, 9800gx2 works just fine. but the 680, when the 8 pin is plugged in, the system wont start. the system also works if the 6 pin power is plugged into the 680 okay we have a misunderstanding here. the 7950 and the 9800gx2 work fine, as in, the power plugs plugged into them work. the gx2's 8 pin works with all of my PSU's 8 pin connections.