I have 5 x Sapphire R9 290 and one of them heats up to 90C for like 7-8 sec (or less). I've put another one in its place with the same power connectors and PCI-E slot and it doesn't have that problem. And I think that this heating is fake because the card feels a lot cooler (on touch) than the others when the sensor says that it is 30+ degrees hotter than them which looks wrong but I can feel only the heat sink and not the chip itself. And that card worked for like 2+ weeks before this happened. What could be the reason ? Sensor failure, thermal paste problem or ... I have no more ideas
Thanks.