Im running Sapphire 5970 and also the 5870 in X-Fire. I'm using the CCC 10.10e driver and installed the 10.12 crossfire app. I'm getting real shitty scores in 3DMark11. I'm talking around 300 points higher at best Also does it matter what position I have the cards in? The 5970 is top slot and the 5870 is in slot #3 as the manual recommends for a second card to be installed in for X-fire mode. Should I change the cards around or does it matter?