unoriginal1 :
http://hardforum.com/showthread.php?p=1039367046
This will explain it. Questions is... Why do you care?
*Edit* Ref or non ref has nothing to do with how well it will cool. Just means they either used or didn't use the original lay out for the board.
Got my HD 7850 at 1120mhz core on stock but would be nice to go further, as it was perfect for 1080p but I have a 1440p monitor now, so would like more horsepower.
Okay thanks, reason why is because I am thinking of overvolting, but am worried about killing it, might not bother as it seems little gain for a big risk, considering it will also use more electric to.