Originally Posted by Yokes29
Hmmm try running one card (top or bottom) at 100% fan speed?
Then see which one is the cooler one?
Primitive way of finding out, i know...
This is a fantastic way to find out.
In Afterburner, you just need to uncheck "Synchronize the settings for similar graphics processors", find out which GPU you are currently viewing from the drop down menu above (ie. GPU 1, GPU 2, etc.), and the manually set the fanspeed to 100% for that GPU. Put your hand behind each card and see which one has the most air coming out.
Just make sure that the other GPU is still at AUTO fan speeds, if it isn't already, and you can monitor the fanspeeds as well, which should correspond correctly to each respective card.