5 ms·

This of course looks very cool, but to me it does not seem practical besides edge-cases, even though the technology is not new in any way, high-powered transfor

by cnvogel 14y ago

This of course looks very cool, but to me it does not seem practical besides edge-cases, even though the technology is not new in any way, high-powered transformers which you find in power plants, for example, are oil-filled since basically forever. The practical problems on the other hand are not to be ignored: The oil needs to be kept rather clean, otherwise it will loose its good insulation properties, hence you need sealed containers or purification devices, in industrial scale deployments this means keeping an eye on the chemical composition of your coolant by regular chemical analysis. Connectors and cables need to be really oil-tight, otherwise the oil will creep out through cables hanging out of a closed vessel (even if they go higher than the oil-surface)! It's not an efficient technology in terms of the amount of coolant that is used: You put everything into the oil-bath, both the high-energy-density components (CPU, graphics-card, maybe chipsets, fast RAM), regardless of their energy consumption: Imagine a full data center, you'd basically need thousands of cubic meters of pure, constantly filtered oil... For the good old cray-computer often used as an example it was different: There computing was spread out over a vast number of logic gates that deposited their waste heat over a really high volume. The examples I have seen (casemodders being a good example) were also rather generous with container-size and amount of coolant where enough circulation and cooling was provided by natural convection. "Professionally", one would use this technology for a reason, hence in devices that are even more densly packed than usual blade-centers and there I expect issues with forced circulations of warm/hot oil just as we have hot/cold air distribution nowadays. A technology like currently deployed water-cooled devices, where the majority of heat is collected by water at the concentration points (mainly CPU) and air is taking care of the (much reduced) remains seems much more sensible to me.

sigkill 14y ago
This may be only partially relevant, but I'm reading about transformer protectors and I can see all sorts of things going wrong here. Extreme heat causes arcing in the oil and consequently fire and/or explosion, in transformers. I don't know how that'd work here.
- mistercow 14y ago
  Arcing is a problem with open air transformers too, and one of the functions of oil in oil-filled transformers is to prevent arcing. Probably this property simply breaks down at very high temperatures, but since arcing isn't generally a problem for computers in the first place, it shouldn't be a problem regardless of oil temperature.
  - lutusp 14y ago
    > Arcing is a problem with open air transformers too, and one of the functions of oil in oil-filled transformers is to prevent arcing. That's part of the reason for oil-filled transformers. The other reason is to cool the heat-generating parts by relying on a liquid's tendency to create convection loops between the warmer and cooler areas. http://en.wikipedia.org/wiki/Transformer_oil http://en.wikipedia.org/wiki/Transformer_oil A quote: "Transformer oil or insulating oil is usually a highly-refined mineral oil that is stable at high temperatures and has excellent electrical insulating properties. It is used in oil-filled transformers, some types of high voltage capacitors, fluorescent lamp ballasts, and some types of high voltage switches and circuit breakers. Its functions are to insulate, suppress corona and arcing, and to serve as a coolant."
    - mistercow 14y ago
      Right, that's why I said "one of".
      - lutusp 14y ago
        I wasn't being critical, only expanding your point.
  - sigkill 14y ago
    That's a good point. Yes, it does break down in certain specific conditions. This causes transformer explosions when there's overload and such. Of course, oil being oil only intensifies this problem.
grandalf 14y ago
In spite of components having different energy densities, all of the components produce some waste heat, so it all has to be dissipated by the cooling system one way or another. In a large datacenter, even the low energy density components (combined across thousands of machines) generate a tremendous amount of heat. Also, it would seem fairly straightforward to design optimized versions of components such as cables to make them better suited for oil, as well as a simple filtration / purity monitoring system.
mistercow 14y ago
>: The oil needs to be kept rather clean, otherwise it will loose its good insulation properties, hence you need sealed containers or purification devices, in industrial scale deployments this means keeping an eye on the chemical composition of your coolant by regular chemical analysis. Considering that they say that it only needs to be changed once a decade, it sounds like they've got that figured out. >Connectors and cables need to be really oil-tight, otherwise the oil will creep out through cables hanging out of a closed vessel (even if they go higher than the oil-surface)! You've already proposed one solution to that problem. Another possibility would be a simple lipophobic coating on a small section of the cable. >you'd basically need thousands of cubic meters of pure, constantly filtered oil... Once again, if it's changed once a decade, that's not really a big deal. >"Professionally", one would use this technology for a reason, hence in devices that are even more densly packed than usual blade-centers and there I expect issues with forced circulations of warm/hot oil just as we have hot/cold air distribution nowadays. OK, but Intel has been testing this in data centers for over a year. This isn't an idea that they're toying with. It's something that has been put into production. >A technology like currently deployed water-cooled devices, where the majority of heat is collected by water at the concentration points (mainly CPU) and air is taking care of the (much reduced) remains seems much more sensible to me. Well, I mean, that should be comparable with numbers. They say this takes energy consumption down to 3%. What are the numbers for water cooling?

by cnvogel 14y ago

sigkill 14y ago

This may be only partially relevant, but I'm reading about transformer protectors and I can see all sorts of things going wrong here. Extreme heat causes arcing in the oil and consequently fire and/or explosion, in transformers. I don't know how that'd work here.

mistercow 14y ago
Arcing is a problem with open air transformers too, and one of the functions of oil in oil-filled transformers is to prevent arcing. Probably this property simply breaks down at very high temperatures, but since arcing isn't generally a problem for computers in the first place, it shouldn't be a problem regardless of oil temperature.
- lutusp 14y ago
  > Arcing is a problem with open air transformers too, and one of the functions of oil in oil-filled transformers is to prevent arcing. That's part of the reason for oil-filled transformers. The other reason is to cool the heat-generating parts by relying on a liquid's tendency to create convection loops between the warmer and cooler areas. http://en.wikipedia.org/wiki/Transformer_oil http://en.wikipedia.org/wiki/Transformer_oil A quote: "Transformer oil or insulating oil is usually a highly-refined mineral oil that is stable at high temperatures and has excellent electrical insulating properties. It is used in oil-filled transformers, some types of high voltage capacitors, fluorescent lamp ballasts, and some types of high voltage switches and circuit breakers. Its functions are to insulate, suppress corona and arcing, and to serve as a coolant."
  - mistercow 14y ago
    Right, that's why I said "one of".
    - lutusp 14y ago
      I wasn't being critical, only expanding your point.
- sigkill 14y ago
  That's a good point. Yes, it does break down in certain specific conditions. This causes transformer explosions when there's overload and such. Of course, oil being oil only intensifies this problem.

grandalf 14y ago

In spite of components having different energy densities, all of the components produce some waste heat, so it all has to be dissipated by the cooling system one way or another. In a large datacenter, even the low energy density components (combined across thousands of machines) generate a tremendous amount of heat. Also, it would seem fairly straightforward to design optimized versions of components such as cables to make them better suited for oil, as well as a simple filtration / purity monitoring system.

mistercow 14y ago

>: The oil needs to be kept rather clean, otherwise it will loose its good insulation properties, hence you need sealed containers or purification devices, in industrial scale deployments this means keeping an eye on the chemical composition of your coolant by regular chemical analysis. Considering that they say that it only needs to be changed once a decade, it sounds like they've got that figured out. >Connectors and cables need to be really oil-tight, otherwise the oil will creep out through cables hanging out of a closed vessel (even if they go higher than the oil-surface)! You've already proposed one solution to that problem. Another possibility would be a simple lipophobic coating on a small section of the cable. >you'd basically need thousands of cubic meters of pure, constantly filtered oil... Once again, if it's changed once a decade, that's not really a big deal. >"Professionally", one would use this technology for a reason, hence in devices that are even more densly packed than usual blade-centers and there I expect issues with forced circulations of warm/hot oil just as we have hot/cold air distribution nowadays. OK, but Intel has been testing this in data centers for over a year. This isn't an idea that they're toying with. It's something that has been put into production. >A technology like currently deployed water-cooled devices, where the majority of heat is collected by water at the concentration points (mainly CPU) and air is taking care of the (much reduced) remains seems much more sensible to me. Well, I mean, that should be comparable with numbers. They say this takes energy consumption down to 3%. What are the numbers for water cooling?