4 ms·

Been there, done that. Useless in a home/lab environment. For a data-center - maybe. In my experience, the oil is far from odourless. It seems that way at firs

Been there, done that. Useless in a home/lab environment. For a data-center - maybe. In my experience, the oil is far from odourless. It seems that way at first, but after a while it saturates the room/house with very annoying smell. Several months later, and I had to get rid of that smell. Even went as far to build stainless steel tanks with gaskets used for car motors. But, when airtight, the whole thing looses it's thermal properties and starts overheating again. I guess because of pressure build-up. So, it is either endure the mineral oil vapors, or nothing. On top of all that, pray you never need to replace/upgrade a component... getting the whole thing out of the oil and cleaning it up so you could handle it again - a nightmare.

imglorp 2y ago
I mean, you can still get Flourinert (!!) and you can pretend you have a Cray. But more seriously, would distilled water work? It should have minimal conductivity in theory. https://www.3m.com/3M/en_US/p/d/b40045180/ https://www.3m.com/3M/en_US/p/d/b40045180/
- MisterTea 2y ago
  I think distilled water would begin to leach metals and whatnot from the PCB making it conductive again. Certainly would need to be continually monitored and watch for corrosion. Flourinert is super expensive, we use it at work for gross leak inspection and filing a single small tank is i think 3-4k USD.
  - qwertox 2y ago
    Distilled water is pretty inexpensive, so flushing it once a month or so would probably work.
    - dan_can_code 2y ago
      I just had the funny thought of flushing my PC like a toilet.
- mystified5016 2y ago
  Distilled water is surprisingly corrosive. Water is actually a very good solvent, but most water you encounter is already so saturated with dissolved minerals and such that it seems mostly inert. Distilled water would work for a while, but will literally dissolve the metals on your board. Conductivity will of course creep up over time, but your main concern should be that the widget you're trying to cool is getting eaten by the coolant. As an example, you may have noticed that air conditioner condensate can damage concrete. The condensate is pretty pure water, and physics really wants it to be less pure. The water is so reactive that it can rip the minerals out of cement, leaving just the aggregate behind. If all that weren't bad enough, once you put a PCB in pure water and it starts leeching ions, you suddenly have an electrolysis bath with dissimilar metals. If you can't maintain the purity of the solution, you'll have a very bad time.
  - HPsquared 2y ago
    Air conditioner condensate is not pure water though, it contains dissolved CO2 from the atmosphere aka carbonic acid. All water in contact with atmospheric air does this. Same with other acid gases, but CO2 is the main one. See also acid rain.
  - deleted 2y ago
    [deleted]
  - madaxe_again 2y ago
    Well, surely you just need a sacrificial anode - nice block of zinc or magnesium wired to earth that you replace once a year.
  - Modified3019 2y ago
    As an aside about pure water being corrosive, ultrapure water is something else, as seen in the Super-Kamiokande neutrino detector https://www.sciencenewslab.com/this-beautiful-golden-chamber-contains-water-so-pure-it-can-dissolve-metal/ https://www.sciencenewslab.com/this-beautiful-golden-chamber... >In order for the light from these shockwaves to reach the sensors, the water has to be cleaner than you can possibly imagine. Super-K is constantly filtering and re-purifying it, and even blasts it with UV light to kill off any bacteria. >Which actually makes it pretty creepy. >“Water that’s ultra-pure is waiting to dissolve stuff into it,” said Uchida. “Pure water is very, very nasty stuff. It has the features of an acid and an alkaline.” >“If you went for a soak in this ultra-pure Super-K water you would get quite a bit of exfoliation,” said Wascko. “Whether you want it or not.” >When Super-K needs maintenance, researchers need to go out on rubber dinghies (see above) to fix and replace the sensors. >Matthew Malek, of the University of Sheffield, and two others were doing maintenance from a dinghy back when he was a PhD student. >At the end of the day’s work, the gondola that normally takes the physicists in and out of the tank was broken, so he and two others had to sit tight for a while. They kicked back in their boats, shooting the breeze. >“What I didn’t realise, as we were laying back in these boats and talking is that a little bit of my hair, probably no more than three centimeters, was dipped in the water,” Malek told Business Insider. >As they were draining the water out of Super-K at the time, Malek didn’t worry about contaminating it. But when he awoke at 3 am the next morning, he had an awful realisation. >“I got up at 3 o’clock in the morning with the itchiest scalp I have ever had in my entire life,” he said. “Itchier than having chickenpox as a child. It was so itchy I just couldn’t sleep.” >He realised that the water had leeched his hair’s nutrients out through the tips, and that this nutrient deficiency had worked its way up to his scalp. He quickly jumped in the shower and spent half an hour vigorously conditioning his hair. >Another tale comes from Wascko, who heard that in 2000 when the tank had been fully drained, researchers found the outline of a wrench at the bottom of it. >“Apparently somebody had left a wrench there when they filled it in 1995,” he said. “When they drained it in 2000 the wrench had dissolved.”
- simne 2y ago
  > would distilled water work? Unfortunately, not, because water is very corrosive, and easy gather many non-inert substances just from air. This is very serious problem. I once talked with old support engineer from USSR, who have some experience with old water-cooled computers. And he said, it was just nightmare, all those pipes periodically leak (some because rot, others become fractured) and in many cases, if water reach pcb, its broke. Really problem was solved on Cray-2 (and later models) by use Fluorinert, which was so inert that was safe to literally drop boards into liquid. Some persons even thinking, Soviets Elbrus was not successful just because USSR don't have companies like DuPont or 3M to produce something similar to Fluorinert.
  - simne 2y ago
    Exists sea grade of electronics, which are covered by thick coating layer, but it is also non-ideal solution, could become fractured, and you cannot make coating on dip switches or on connectors.
  - wbl 2y ago
    Fluorinert was absolutely something the USSR could produce. You need fluoromers and fluorine chemistry for nuclear technology.
    - simne 2y ago
      > Fluorinert was absolutely something the USSR could produce May be. But in fact - not produced. And Soviet Elbrus computers used water cooling with extreme problems. - I'm 100% sure, if it was possible for Elbrus designers to use Fluorinert, it would be used, but it was impossible, so not used.
JumpCrisscross 2y ago
> when airtight, the whole thing looses it's thermal properties and starts overheating again. I guess because of pressure build-up Does the oil actuallly avoid heating up that much by expanding?
- atmanactive 2y ago
  It seems so. I would drill a 1mm diameter hole at the top to release the pressure and the temperatures would immediately drop. But then we are back to that horrible, horrible smell. I'm guessing that's why nobody sits next to powergrid AC/AC transformers (also submerged in mineral oil) but they are always secluded in a small room or left hanging high up on the pole. It's simply inhuman, that oil.
  - guenthert 2y ago
    > powergrid AC/AC transformers (also submerged in mineral oil) Older ones might use toxic materials like PCB though.
ycombinatrix 2y ago
>The custom mineral oil pc project has always been intended as a cool conversation piece Sounds like it worked :)
stronglikedan 2y ago
> Useless in a home/lab environment. Could you do something like a mini-split and put that half outside?
- atmanactive 2y ago
  Yes, but then again, you could do that with any approach, even turbine-grade fans for loud air cooling. It kind of defeats the purpose.
  - 542354234235 2y ago
    I think you misunderstand the purpose of immersion. You still have to dissipate and radiate the heat. You can’t just do it with “any approach” because air, as a medium, cannot conduct as much heat. You will reach a maximum in air long before you reach a max in mineral oil. But it isn’t magic. The heat has to go somewhere. That is why liquid coolers have radiators and why air-cooled cases have vents to the outside.
    - atmanactive 2y ago
      Yes, a stainless steel tank has thousand times more surface to disipate the heat away than a bare CPU. Same with 1-kilo heatsinks, like, for example, Noctua NH-P1 which I am using for passive air cooling today.
      - BenjiWiebe 2y ago
        And a radiator the size of the tank probably has another 1000x better heat transfer than the tank.
        atmanactive 2y ago
        Absolutely. It's all about heat exchange contact area, nothing more. Contact area can be increased by fins, or simply by mass. A cubic meter copper cube would still cool down a CPU adequately even without a single fin. Of course, fins are space-saving so everyone uses them.
HPsquared 2y ago
If it was airtight and there were heat transfer problems, the first thing I'd think is the pressure is probably below atmospheric and the fluid is boiling (or cavitating the pump if there is one). Say, if it was filled to the top while warm, then sealed, the pressure would drop as the oil dropped to room temperature and contracted (or not, depending on differential rates of thermal expansion cf the container). Some air space at the top of the sealed container (preferably dry air or nitrogen) would fix that. Make sure there's a pressure gauge and some means of preventing overpressure, though.
- 542354234235 2y ago
  It sounds like they didn't circulate the fluid through radiators and were just relying on natural convection to circulate the fluid and the open tank allowed for heat from the fluid to be dissipated into the air. So sealing it would cause it to overheat immediately, same as if you saran wrapped an air-cooled PC.
  - atmanactive 2y ago
    As a matter of fact it wouldn't overheat immediately but some 15-20 hours later. Very strange. As soon as it wasn't sealed, it would stop overheating and would transfer the heat steadily for weeks. Keep in mind that the whole tank was stainless steel with some 50 liters of oil inside, hence the oil-to-air transfer was more than adequate.
    - 542354234235 2y ago
      That makes sense, because it took 15-20 hours for all that oil to become fully heated and reach its carrying capacity. Your stainless steel tank and passive conduction was obviously not adequate, or you wouldn’t have overheating problems. When it was unsealed, the air convection across the top of the tank carried enough heat that it wouldn’t overheat. In another comment you say you use a passive cooling Noctua heatsink. If you seal up your PC with shrink wrap, your CPU will still overheat due to the lack of that same air convection. In a sealed system, you have to actively move liquid through radiators. You can move as much heat as you want into a heatsink, if there isn’t a way to move heat quickly out of the heatsink, then you aren't doing anything.
542354234235 2y ago
>when airtight, the whole thing looses it's thermal properties and starts overheating again Were you pumping the fluid through radiators? It doesn’t really sound like you were, which would be the obvious reason it would overheat. You have to actually transfer and dissipate the heat. What makes the immersion cooling so good is that it conducts heat so much better than air, you can add giant radiators and dissipate an ungodly amount of heat, so can run your equipment ungodly fast. You can’t just drop it into an aquarium of mineral oil and expect it to do much.
JKCalhoun 2y ago
> It has also allowed an overclock of a QX9770 from a stock frequency of 3.2GHz, to an overclocked frequency of 4.6GHz! I never understood the over-clocking obsession. Wait 6 months and the new hardware coming out will run faster than your mineral oil computer and cost the same as it always has.
- IntelMiner 2y ago
  Factually untrue
  - JKCalhoun 2y ago
    Is that right? Was there some kind of ceiling at 3.2 GHz?
    - IntelMiner 2y ago
      Where'd I say that? Clockspeed isn't everything
- toast0 2y ago
  a) finding out what's really possible vs what it says on the box can be fun b) buying a lower cost model and getting similar performance to what you get from a higher cost model out of the box is a good value c) sometimes you really need more performance, so nothing else will do d) modern overclocking is more about tuning voltages lower, but not too low, so you generate less heat and can clock a bit higher, which can end up saving energy.

imglorp 2y ago

I mean, you can still get Flourinert (!!) and you can pretend you have a Cray. But more seriously, would distilled water work? It should have minimal conductivity in theory. https://www.3m.com/3M/en_US/p/d/b40045180/ https://www.3m.com/3M/en_US/p/d/b40045180/

MisterTea 2y ago
I think distilled water would begin to leach metals and whatnot from the PCB making it conductive again. Certainly would need to be continually monitored and watch for corrosion. Flourinert is super expensive, we use it at work for gross leak inspection and filing a single small tank is i think 3-4k USD.
- qwertox 2y ago
  Distilled water is pretty inexpensive, so flushing it once a month or so would probably work.
  - dan_can_code 2y ago
    I just had the funny thought of flushing my PC like a toilet.
mystified5016 2y ago
Distilled water is surprisingly corrosive. Water is actually a very good solvent, but most water you encounter is already so saturated with dissolved minerals and such that it seems mostly inert. Distilled water would work for a while, but will literally dissolve the metals on your board. Conductivity will of course creep up over time, but your main concern should be that the widget you're trying to cool is getting eaten by the coolant. As an example, you may have noticed that air conditioner condensate can damage concrete. The condensate is pretty pure water, and physics really wants it to be less pure. The water is so reactive that it can rip the minerals out of cement, leaving just the aggregate behind. If all that weren't bad enough, once you put a PCB in pure water and it starts leeching ions, you suddenly have an electrolysis bath with dissimilar metals. If you can't maintain the purity of the solution, you'll have a very bad time.
- HPsquared 2y ago
  Air conditioner condensate is not pure water though, it contains dissolved CO2 from the atmosphere aka carbonic acid. All water in contact with atmospheric air does this. Same with other acid gases, but CO2 is the main one. See also acid rain.
- deleted 2y ago
  [deleted]
- madaxe_again 2y ago
  Well, surely you just need a sacrificial anode - nice block of zinc or magnesium wired to earth that you replace once a year.
- Modified3019 2y ago
  As an aside about pure water being corrosive, ultrapure water is something else, as seen in the Super-Kamiokande neutrino detector https://www.sciencenewslab.com/this-beautiful-golden-chamber-contains-water-so-pure-it-can-dissolve-metal/ https://www.sciencenewslab.com/this-beautiful-golden-chamber... >In order for the light from these shockwaves to reach the sensors, the water has to be cleaner than you can possibly imagine. Super-K is constantly filtering and re-purifying it, and even blasts it with UV light to kill off any bacteria. >Which actually makes it pretty creepy. >“Water that’s ultra-pure is waiting to dissolve stuff into it,” said Uchida. “Pure water is very, very nasty stuff. It has the features of an acid and an alkaline.” >“If you went for a soak in this ultra-pure Super-K water you would get quite a bit of exfoliation,” said Wascko. “Whether you want it or not.” >When Super-K needs maintenance, researchers need to go out on rubber dinghies (see above) to fix and replace the sensors. >Matthew Malek, of the University of Sheffield, and two others were doing maintenance from a dinghy back when he was a PhD student. >At the end of the day’s work, the gondola that normally takes the physicists in and out of the tank was broken, so he and two others had to sit tight for a while. They kicked back in their boats, shooting the breeze. >“What I didn’t realise, as we were laying back in these boats and talking is that a little bit of my hair, probably no more than three centimeters, was dipped in the water,” Malek told Business Insider. >As they were draining the water out of Super-K at the time, Malek didn’t worry about contaminating it. But when he awoke at 3 am the next morning, he had an awful realisation. >“I got up at 3 o’clock in the morning with the itchiest scalp I have ever had in my entire life,” he said. “Itchier than having chickenpox as a child. It was so itchy I just couldn’t sleep.” >He realised that the water had leeched his hair’s nutrients out through the tips, and that this nutrient deficiency had worked its way up to his scalp. He quickly jumped in the shower and spent half an hour vigorously conditioning his hair. >Another tale comes from Wascko, who heard that in 2000 when the tank had been fully drained, researchers found the outline of a wrench at the bottom of it. >“Apparently somebody had left a wrench there when they filled it in 1995,” he said. “When they drained it in 2000 the wrench had dissolved.”
simne 2y ago
> would distilled water work? Unfortunately, not, because water is very corrosive, and easy gather many non-inert substances just from air. This is very serious problem. I once talked with old support engineer from USSR, who have some experience with old water-cooled computers. And he said, it was just nightmare, all those pipes periodically leak (some because rot, others become fractured) and in many cases, if water reach pcb, its broke. Really problem was solved on Cray-2 (and later models) by use Fluorinert, which was so inert that was safe to literally drop boards into liquid. Some persons even thinking, Soviets Elbrus was not successful just because USSR don't have companies like DuPont or 3M to produce something similar to Fluorinert.
- simne 2y ago
  Exists sea grade of electronics, which are covered by thick coating layer, but it is also non-ideal solution, could become fractured, and you cannot make coating on dip switches or on connectors.
- wbl 2y ago
  Fluorinert was absolutely something the USSR could produce. You need fluoromers and fluorine chemistry for nuclear technology.
  - simne 2y ago
    > Fluorinert was absolutely something the USSR could produce May be. But in fact - not produced. And Soviet Elbrus computers used water cooling with extreme problems. - I'm 100% sure, if it was possible for Elbrus designers to use Fluorinert, it would be used, but it was impossible, so not used.

JumpCrisscross 2y ago

> when airtight, the whole thing looses it's thermal properties and starts overheating again. I guess because of pressure build-up Does the oil actuallly avoid heating up that much by expanding?

atmanactive 2y ago
It seems so. I would drill a 1mm diameter hole at the top to release the pressure and the temperatures would immediately drop. But then we are back to that horrible, horrible smell. I'm guessing that's why nobody sits next to powergrid AC/AC transformers (also submerged in mineral oil) but they are always secluded in a small room or left hanging high up on the pole. It's simply inhuman, that oil.
- guenthert 2y ago
  > powergrid AC/AC transformers (also submerged in mineral oil) Older ones might use toxic materials like PCB though.

ycombinatrix 2y ago

>The custom mineral oil pc project has always been intended as a cool conversation piece Sounds like it worked :)

stronglikedan 2y ago

> Useless in a home/lab environment. Could you do something like a mini-split and put that half outside?

atmanactive 2y ago
Yes, but then again, you could do that with any approach, even turbine-grade fans for loud air cooling. It kind of defeats the purpose.
- 542354234235 2y ago
  I think you misunderstand the purpose of immersion. You still have to dissipate and radiate the heat. You can’t just do it with “any approach” because air, as a medium, cannot conduct as much heat. You will reach a maximum in air long before you reach a max in mineral oil. But it isn’t magic. The heat has to go somewhere. That is why liquid coolers have radiators and why air-cooled cases have vents to the outside.
  - atmanactive 2y ago
    Yes, a stainless steel tank has thousand times more surface to disipate the heat away than a bare CPU. Same with 1-kilo heatsinks, like, for example, Noctua NH-P1 which I am using for passive air cooling today.
    - BenjiWiebe 2y ago
      And a radiator the size of the tank probably has another 1000x better heat transfer than the tank.
      - atmanactive 2y ago
        Absolutely. It's all about heat exchange contact area, nothing more. Contact area can be increased by fins, or simply by mass. A cubic meter copper cube would still cool down a CPU adequately even without a single fin. Of course, fins are space-saving so everyone uses them.

HPsquared 2y ago

If it was airtight and there were heat transfer problems, the first thing I'd think is the pressure is probably below atmospheric and the fluid is boiling (or cavitating the pump if there is one). Say, if it was filled to the top while warm, then sealed, the pressure would drop as the oil dropped to room temperature and contracted (or not, depending on differential rates of thermal expansion cf the container). Some air space at the top of the sealed container (preferably dry air or nitrogen) would fix that. Make sure there's a pressure gauge and some means of preventing overpressure, though.

542354234235 2y ago
It sounds like they didn't circulate the fluid through radiators and were just relying on natural convection to circulate the fluid and the open tank allowed for heat from the fluid to be dissipated into the air. So sealing it would cause it to overheat immediately, same as if you saran wrapped an air-cooled PC.
- atmanactive 2y ago
  As a matter of fact it wouldn't overheat immediately but some 15-20 hours later. Very strange. As soon as it wasn't sealed, it would stop overheating and would transfer the heat steadily for weeks. Keep in mind that the whole tank was stainless steel with some 50 liters of oil inside, hence the oil-to-air transfer was more than adequate.
  - 542354234235 2y ago
    That makes sense, because it took 15-20 hours for all that oil to become fully heated and reach its carrying capacity. Your stainless steel tank and passive conduction was obviously not adequate, or you wouldn’t have overheating problems. When it was unsealed, the air convection across the top of the tank carried enough heat that it wouldn’t overheat. In another comment you say you use a passive cooling Noctua heatsink. If you seal up your PC with shrink wrap, your CPU will still overheat due to the lack of that same air convection. In a sealed system, you have to actively move liquid through radiators. You can move as much heat as you want into a heatsink, if there isn’t a way to move heat quickly out of the heatsink, then you aren't doing anything.

542354234235 2y ago

>when airtight, the whole thing looses it's thermal properties and starts overheating again Were you pumping the fluid through radiators? It doesn’t really sound like you were, which would be the obvious reason it would overheat. You have to actually transfer and dissipate the heat. What makes the immersion cooling so good is that it conducts heat so much better than air, you can add giant radiators and dissipate an ungodly amount of heat, so can run your equipment ungodly fast. You can’t just drop it into an aquarium of mineral oil and expect it to do much.

JKCalhoun 2y ago

> It has also allowed an overclock of a QX9770 from a stock frequency of 3.2GHz, to an overclocked frequency of 4.6GHz! I never understood the over-clocking obsession. Wait 6 months and the new hardware coming out will run faster than your mineral oil computer and cost the same as it always has.

IntelMiner 2y ago
Factually untrue
- JKCalhoun 2y ago
  Is that right? Was there some kind of ceiling at 3.2 GHz?
  - IntelMiner 2y ago
    Where'd I say that? Clockspeed isn't everything
toast0 2y ago
a) finding out what's really possible vs what it says on the box can be fun b) buying a lower cost model and getting similar performance to what you get from a higher cost model out of the box is a good value c) sometimes you really need more performance, so nothing else will do d) modern overclocking is more about tuning voltages lower, but not too low, so you generate less heat and can clock a bit higher, which can end up saving energy.