3 ms·

Definitely, thermal paste is the answer for any practical application. Ah you’re right. I was thinking of experiments with indium foil I had seen[1]. Plus gall

Definitely, thermal paste is the answer for any practical application. Ah you’re right. I was thinking of experiments with indium foil I had seen[1]. Plus gallium is used in the pastes apparently. So if the goal is a very long term thermal interface material, I don’t think pastes are the best. A homogenous solid is likely to last longer. Indium foil fits the bill nicely. Also thermal pads or graphite pads, but I’m not sure how long they last. [1] https://www.reddit.com/r/buildapc/comments/99fq4y/experiments_with_indium_instead_of_thermal_paste/ https://www.reddit.com/r/buildapc/comments/99fq4y/experiment...

bayindirh 5y ago
> So if the goal is a very long term thermal interface material, I don’t think pastes are the best. A homogenous solid is likely to last longer. Arctic Cooling states that MX-5 is guaranteed to keep its performance its for 8 years [0]. Considering this stuff is made to interface with 200W+ CPUs, cooking it dry with a Raspberry Pi is very unlikely. As I said before, I'm cooking MX-2 in two different systems (Q6600 & i7 3770K) for 8 years, and they didn't lose their transfer performance a bit. From my experience, thermal pads and solid interfaces do not transfer with the same efficiency and cannot absorb heat spikes as well as a good thermal paste. I run my OrangePi Zero with a thermal pad interface to a small heat-sink and that thing runs uncomfortably hot. I can't transfer data faster than 40mbps for a long time or run CPU intensive stuff, because it gets hot, fast. Its form factor and case doesn't allow for a more robust solution either. Of course the choice is yours, but in my experience, when compared to older paste, or to ordinary white stuff, current generation stuff is leaps and bounds ahead. Especially, Arctic Cooling. [0]: https://www.arctic.de/en/MX-5/ACTCP00047A https://www.arctic.de/en/MX-5/ACTCP00047A
- labawi 5y ago
  Thermal pads are way thicker and typically higher resistance - even good and thin ones are worse than standard paste and basically useless over a dozen watts (depending on surface area * temperature difference). OTOH, used properly, liquid (liquefying) metal should have a better transfer efficiency than paste. If you have issues, you can also try lapping the surfaces.
  - bayindirh 5y ago
    The sinks I use have 3M integrated pads. They might not be the highest performing ones, but they're pretty decent for their size. As I've said, it's attached to a OrangePi Zero which has a very small, epoxy packaged CPU. So tension-mounting, lapping, or using higher end compounds are out of question. The whole point of OrangePi Zero is being small all over, so it's happy temp-wise with its normal load, I'm not planning to work on it further for now. Raspberry Pi 4 is different and has a whole-body heatsink, and its paste is good for now. If it starts to lose cooling capacity, that'll be a different matter all-over.

bayindirh 5y ago

> So if the goal is a very long term thermal interface material, I don’t think pastes are the best. A homogenous solid is likely to last longer. Arctic Cooling states that MX-5 is guaranteed to keep its performance its for 8 years [0]. Considering this stuff is made to interface with 200W+ CPUs, cooking it dry with a Raspberry Pi is very unlikely. As I said before, I'm cooking MX-2 in two different systems (Q6600 & i7 3770K) for 8 years, and they didn't lose their transfer performance a bit. From my experience, thermal pads and solid interfaces do not transfer with the same efficiency and cannot absorb heat spikes as well as a good thermal paste. I run my OrangePi Zero with a thermal pad interface to a small heat-sink and that thing runs uncomfortably hot. I can't transfer data faster than 40mbps for a long time or run CPU intensive stuff, because it gets hot, fast. Its form factor and case doesn't allow for a more robust solution either. Of course the choice is yours, but in my experience, when compared to older paste, or to ordinary white stuff, current generation stuff is leaps and bounds ahead. Especially, Arctic Cooling. [0]: https://www.arctic.de/en/MX-5/ACTCP00047A https://www.arctic.de/en/MX-5/ACTCP00047A

labawi 5y ago
Thermal pads are way thicker and typically higher resistance - even good and thin ones are worse than standard paste and basically useless over a dozen watts (depending on surface area * temperature difference). OTOH, used properly, liquid (liquefying) metal should have a better transfer efficiency than paste. If you have issues, you can also try lapping the surfaces.
- bayindirh 5y ago
  The sinks I use have 3M integrated pads. They might not be the highest performing ones, but they're pretty decent for their size. As I've said, it's attached to a OrangePi Zero which has a very small, epoxy packaged CPU. So tension-mounting, lapping, or using higher end compounds are out of question. The whole point of OrangePi Zero is being small all over, so it's happy temp-wise with its normal load, I'm not planning to work on it further for now. Raspberry Pi 4 is different and has a whole-body heatsink, and its paste is good for now. If it starts to lose cooling capacity, that'll be a different matter all-over.