While there are some standardised methods for testing the thermal conductivity or thermal resistance of thermal compounds, they do not always guarantee comparable results. What's more, many vendors have started to claim thermal resistance or thermal conductivity specifications that appear simply unrealistic in the light of standardised testing. Finally, real-world performance of thermal compounds is affected by various other factors such as spreading properties, bond line thickness, mounting pressure or contact quality, so even if there was a common and reliable industry standard for testing the thermal conductivity or resistance of thermal pastes, it would not give customers a clear indication regarding the performance they can expect. 

For these reasons, Noctua has chosen not to publish specifications for thermal conductivity and resistance. Taking part in a game of claiming exaggerated specifications is not an option for us and we neither want to give specifications that, in the context of this practice, could appear misleading. Instead, we prefer to let independent reviewers judge the performance of our thermal compounds versus competing solutions in order to help customers in making an informed buying decision. Please refer to our standardised comparison of NT-H1 vs NT-H2 and to our review database for independent tests.