The problem is that the VRM are blowing on the cards. And the reason is auto fan. The VRM have their own heat sink which is cooled by the main fans. However as auto fan adjusts the fan speed for the GPU temp and not the VRM temp the VRM can over heat and the fans will not rev up. I have my cards under volted and they run at about 68c so with a target temp of 70c the fans are running at only 20%. Make sure if you have these cards (or any other without VRM temp control) that you set your fans at 100%. They are rated for 30,000 hours (3.5 years) at that speed.