my stable speed is 50mhz faster than yours.. Every 6600 and 6800 ive ever opened (i build a lot of high end systems.) comes with a sli clip, aswell as the motherboards.. If you compare the tyan dual operton sli board, the gigabyte, and the asus you will see what im talking about.. Tyan and gigabyte are standard.. it is laid out pcie, pcx, pcie, pcx instead of pcie, pcx pcx, pcie..
the a8n-sli is like 150 and the gigabyte is 175ish