XtremeSystems forum members speculated AMD may had to delay its Radeon HD 6900 series because the corner of the inner 6/8-pin power connector blocked the cooling solution:
Perhaps it's jumping to conclusions but it's a quite interesting observation.
If you unmount the cooler of a reference card, you could notice an obvious abrasion over the corner of the inner 6/8-pin power
connector socket. No, it ain't by chance you've got a bad pick. It's common among all the popular review sites.
Yes, it's because if you don't polish that corner, you wouldn't be able to mount and install that cooler! Thus AMD spent a delay
to fix that - they polish every card by hand, therefore each card is guaranteed to be a hand-crafted unique version!