Three times more efficient than copper. http://www.bit-tech.net/news/hardware/2015/07/02/litecool-black-x/1
I really want to ask that as well but as Mr H didn't specifically mention its possible use in GPU/CPU I didn't want to risk being lambasted.
Mr H didn't mention its use in other domains, 'cos Mr H has no idea whether it could be used in other domains and didn't want to say so. My guess would be that, in theory, it would be possible to use Black X in place of copper for heatsinks and shims; it would, however, depend on whether it can be formed into the shapes required rather than a thin, flat layer and how much it would cost to do so compared with copper. It's no good being three times more efficient than copper if it costs a hundred times as much...
