Liquid metal thermal paste has been touted as a better alternative to traditional thermal paste for those that really want the best performance out of their PC. However, it is a bit of a hassle to work with, can be very messy and it also has a few risks associated with it that should be weighed out carefully before using. The main risk with liquid metal is that it is not only very good at conducting heat but it is also a very good conductor of electrical current so it could potentially fry your motherboard if you get any of it on the bare chips or in the socket. Liquid metal is also corrosive, especially with aluminum so it is generally only used on systems that will use copper heat sinks.
Unlike standard silicon-based thermal compounds that use a mixture of silicone oil and zinc oxide as the gap-filler, liquid metal is based on pure metals like gallium and indium. The liquid is then spread across the CPU or GPU’s IHS and the cooler to fill any microscopic gaps between them and ensure that there is a smooth surface for maximum heat transfer.
While the thermal conductivity is much better than silicone-based TIMs, it still isn’t as good as a proper heatsink. As such, it is usually only used on builds that will run at very high temperatures or for overclocking. It’s a lot harder to apply than normal thermal paste and needs to be carefully brushed on so that it doesn’t smear or get onto other components.