I've been informed directly by Bitmain that the external heatsinks have basically little or no effect on cooling, which is why the only shipped a few miners with these mini heatsinks.
Probably a waste of time/money IMO.
Hah i see. Thanks for your reply.
Maybe OP has something to say about that, i think he had a heatsink'd unit and a non heatsink'd unit side by side. I'm always worried something not appearing on temp sensor overheating.