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BarneyP

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    BarneyP got a reaction from Bigdaddyhawk in Pure Gallium instead of liquid metal thermal compound   
    The thermal conductivity claims of metal TIM manufacturers are absolute and utter lies. When you alloy two metals, the thermal conductivity is always much lower than the the thermal conductivity of either constituent. It is physically impossible for an alloy of indium and gallium to have a thermal conductivity even close to that of pure gallium, unless the proportion of indium is huge - in which case the alloy would not be a liquid anywhere near room temperature.
     
    Addition of silver (or any other high thermal conductivity metal) can only reduce thermal conductivity further. For the addition of silver to increase thermal conductivity, it would need to make up about 50% of the alloy. Such an alloy would have a melting point of around 500 degrees Celsius (search for "Ag Ga phase diagram").
     
    Manufacturers can get away with claiming whatever the hell they like about the physical properties of their products, because nobody has the time, energy, money or motivation to take them to court over it.
     
    Eutectic gallium/indium (known as eGaIn) performs identically to Coollaboratory's and Thermal Grizzly's products (I've made it, and I've tested it extensively - it actually marginally outperforms both - presumably because it doesn't contain any tin). Its thermal conductivity is 24.9 W⋅m. K−1. That's as good as it gets.
  2. Informative
    BarneyP got a reaction from slippers_ in Is Intel in 2019 = AMD in the early 2010s?   
    In the desktop market, Intel should be worried, but their situation is not as bad as AMD's was a few years back.
     
    In the server market ... Intel look to be in massive, massive trouble. Epyc Rome puts them to shame to a quite ridiculous extent. In some areas of the product stack AMD are offering 3 and even 4 times instructions per second per dollar. Not only 3-4 times bang for buck. By practically every criterion, Epyc Rome soundly thrashes Intel - much more so than Intel was ever thrashing AMD in the desktop or server market, performance-wise.
     
    And the server market is much more lucrative. 
  3. Informative
    BarneyP got a reaction from Ross Siggers in Using alcohol inks directly on motherboard - is this idea insane?   
    Trying to do a bit more research on it myself. Every query I try just gives me loads of tips about using them, but no no "scientific" analysis (fair enough, why would I expect otherwise?).
     
    Did find the full product sheet for one manufacturer's inks which gave a breakdown: alcohol (fine, widely known to be safe on electronics); 2-propoxyethanol (a form of anti-freeze, conductivity < 1e-6 mhos, which I think makes it an insulator to all intents and purposes); "polymers" (sic), which I assume are like any other plastics very good insulators, and (1-2%) "pigments" (sic).
     
    Obviously the alcohol will evaporate almost instantly. My gut feeling is that there wouldn't be enough of the other ingredients there to worry about blistering or flaking, but only testing could verify that. I imagine the biggest concern is whether the pigments might be conductive.
     
    I'm going to be buying some alcohol inks in any case (to see whether I can stain an aluminium heatsink/cooler to look reasonably like weathered copper)
    and I have an old and useless graphics card on which I can test the direct application of alcohol inks on a PCB.
     
    If I get round to trying this, I promise to report back here.
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