Reflections on watercooling: Difference between revisions
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TIM is thermally conductive viscous material applied between heat contacts. There's some between your dies and the IHS, and then some between the IHS and your waterblock/heatsink. Its purpose is to smooth out the conducting surface, which is dotted with microscopic pits that would otherwise preclude contact. TIM is one or two orders of magnitude less thermally conductive than metals making direct contact, but much more conductive than the air which would otherwise fill these regions. Thermal conductance is measured in W/Km (watts per kelvin-meter). | TIM is thermally conductive viscous material applied between heat contacts. There's some between your dies and the IHS, and then some between the IHS and your waterblock/heatsink. Its purpose is to smooth out the conducting surface, which is dotted with microscopic pits that would otherwise preclude contact. TIM is one or two orders of magnitude less thermally conductive than metals making direct contact, but much more conductive than the air which would otherwise fill these regions. Thermal conductance is measured in W/Km (watts per kelvin-meter). | ||
* I don't delid my processors, but it's an intriguing idea. Delidding is the removal of the processor's integrated heat spreader. The IHS is the metal cover atop your processor. The actual heat-generating die elements tend to be only a small portion of this total area (the remainder is mostly devoted to pins). Delidding is a bet that you have better thermal interface material than what was used between the die(s) and the IHS. This was absolutely true in the past, but modern processors often use an indium soldering solution that is just about as good, IMHO, as anything you're going to do. | * I don't delid my processors, but it's an intriguing idea. Delidding is the removal of the processor's integrated heat spreader. The IHS is the metal cover atop your processor. The actual heat-generating die elements tend to be only a small portion of this total area (the remainder is mostly devoted to pins). Delidding is a bet that you have better thermal interface material than what was used between the die(s) and the IHS. This was absolutely true in the past, but modern processors often use an indium soldering solution that is just about as good, IMHO, as anything you're going to do. | ||
* Liquid metal is conductive thermal paste. It is more thermally conductive than non-metal pastes, which is Good. It will short out any electronics it touches, which is Bad. I don't mess with it. The place to use liquid metal IMHO is between the die and IHS when delidding. In this case it's contained, and you're usually replacing a crap TIM. Liquid metal's thermal conductance is no better than a good indium solder, so there's just no point with a good die-to-IHS TIM. Atop the IHS, it's unlikely that liquid metal will beat quality non-conducting paste by more than one or two degrees. | * Liquid metal is electrically conductive thermal paste. It is more thermally conductive than non-metal pastes, which is Good. It will short out any electronics it touches, which is Bad. I don't mess with it. The place to use liquid metal IMHO is between the die and IHS when delidding. In this case it's contained, and you're usually replacing a crap TIM. Liquid metal's thermal conductance is no better than a good indium solder, so there's just no point with a good die-to-IHS TIM. Atop the IHS, it's unlikely that liquid metal will beat quality non-conducting paste by more than one or two degrees. | ||
* No matter your cooling strategy, you'll be fucked without properly-applied high-quality thermal paste. It is easy to apply too little or too much. Application of the waterblock/heatsink will spread the paste for you; you want a very thin layer across the entirety of the integrated heat spreader. A thick layer will absolutely cause problems. Thermal paste ought be replaced every few years, theoretically. | * No matter your cooling strategy, you'll be fucked without properly-applied high-quality thermal paste. It is easy to apply too little or too much. Application of the waterblock/heatsink will spread the paste for you; you want a very thin layer across the entirety of the integrated heat spreader. A thick layer will absolutely cause problems. Thermal paste ought be replaced every few years, theoretically. | ||