The throttling can be brief, it typically occurs in spurts (micro-throttling) to reduce the observable impact. That said, if you can transfer 253GB of data before the throttling kicks in, a heatsink really isn't necessary. It is cool, though.Samsung attacked thermal throttling from several angles. The Polaris controller runs cool during general desktop use, but it has a high thermal ceiling. Samsung highlights the thin copper strip that it embedded in the 960 EVO's label, but we have our doubts about its effectiveness. For what it is worth, there is a thin copper strip between the adhesive layers and printed layer on the label. The company placed several copper layers under the black paint, and the printed circuit board also features a larger, thicker copper layer that is in closer proximity to the heat source.
Throttling seems to occur in stages to minimize the impact on the user experience. The 960 EVO can operate a full 16 seconds longer than the 950 Pro before the dynamic thermal guard (DTG) triggers and reduces performance to maintain a safe thermal envelope. That allows 60% more data to transfer, which is a full 253GB of data during sequential reads on 512GB-class products.