The passive test helps to identify how effective the heatsink design can dissipate heat without the use of cooling fans. In this test we are relying solely on the thermal design and options Thermalright have opted for. As you can see from the results, the gap has now reduced between Silver Arrow SB-E Extreme but it still remains at the top of our list. Its materials, fin design and heatpipes help to maintain top performance. Regardless of the cooling fans, Silver Arrow SB-E Extreme is proven to have an effective cooling design.