Originally Posted by Thanh Nguyen
Has anyone tried liquid gallium vs conductonaunt? 40.3 vs 70.6 but the seller says liquid gallium is better. I bet if it is better, its just 1c. I plan to test it out on my gpu but too busy lately so did not have time for it.
There is NO SUCH THING as "Liquid gallium". Gallium is a solid at room temperature but it melts at about 30C. Gallium cannot be used as a raw thermal compound because it will harden and expand when it cools and will either completely destroy the die or will destroy the heat transfer properties when it hardens.
All Liquid metals (Gallium based alloys) that are suitable for CPU heat transfer cooling (not on aluminum heatsinks!!!!) are "Galinstan" alloys, consisting of Gallium (about 65%), Indium (about 25%) and Tin (about 10%). Some may contain trace (<2%) amounts of bismuth and antimony to help wetting (spreading) and anti-oxidation. Some commercial mixtures may have a higher indium content. Gallium by itself is only about 40 w/mk, and cannot be used by itself.
Eutectic alloys like Galinstan have their W/mk *Lower* than the lowest w/mk metal in the mixture. So while Indium is 82 w/mk and Tin is 67 w/mk, Gallium, the most plentiful component is 40.5 w/mk, and mixing these three metals together lowers the melting point of the metal that melts at the lowest temp (Gallium --at about 30C), to around 0 to -8C. But the heat transfer properties of the "Galinstan" compound will be *substantially* lower than 40.5 W/mk !! It's more like 25-30 w/mk in actuality.
Anyone that tries to tell you otherwise is full of **CRAP**. Even Thermal Grizzly lies about their w/mk levels, so does Thermalright Silver King. (Silver King uses the indium w/mk rating).