I cannot possibly find any concrete information as to the highest achievable overclock which is deemed safe on 480s equipped with Samsung memory modules.  

Any insight would be helpful.

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Edit
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I have decided to dedicate this thread to all GDDR5 memory modules which come equipped with the latest cards available from AMD as well as Nvidia instead of constraining it to the RX 480.  You are most welcome to share modules for older architectures and to those fortunate enough to own a thermal camera, please share corresponding temperatures.  To those savvy enough to determine the maximum temperatures which are deemed safe for particular modules, please do not hesitate to share your input.