Thermalright AXP-100 Full Copper and AXP-100 Full Copper Graphene Edition are now available in China. While technically not passive CPU coolers, we know for a fact that the original AXP-100 can handle a 35W CPU in some scenarios. So these 600 grams newcomers could show some potential in passive mode. For reference, "official" fanless CPU coolers like Arctic Alpine 12 Passive and Nofan CR-80EH are 508 and 300 grams respectively.
Source:
coolaler
