Generally we prefer AMD cards as most (profitable) mining functions are memory bandwidth dominated. Usually it's a shader unit that gets unstable in the 70-80C

Generally we prefer AMD cards as most (profitable) mining functions are memory bandwidth dominated. Usually it's a shader unit that gets unstable in the 70-80C range (note that most silicon is rated for higher ranges). AMD's hardware specifications are more open too which lets one build your own shader compilers and get direct access to the iron.