[SOLVED] Under water Cylindrical PC server

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Atevoh

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Greetings,

I am a chemist inquiring on how to build a submergible underwater computer and just had a few questions regarding such. The computer needs to be put into a cylindrical case that is 12 by 4 inches in diameter so I plan on using a Pico-ITX motherboard but was curious if i wanted to go fanless with this build what would be the best processor for moderate to even low end processing power but has a very low TDP and wouldn't output that much heat. The environment (the water) in this scenario would be helping to cool the server so it wouldn't need to be the lowest TDP processor out there, just a lower end one that still can provide some punch. If there is anyone who can that would be fantastic! Thank you so much.

Sincerely,

Harrison
 
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Temps will vary. Something used in the upper 2m or so surface area (especially in tropical regions) is going to have a much harder time dissipating heat. Start dropping down and temperature gradients will solve all that, at 30m you'd not need a heatsink for a directly connected 10900k overclocked to the moon.

The motherboard itself and any storage are going to be the issue in warmer waters as the case itself will not transfer much heat when there's little temp difference inside to outside. Fans won't help because of the enclosure, 72°C air is still 72°C whether it's moving or not.

Watertight fittings aren't an issue, it's the same theory behind a wired AV, just different cables.

I'd suggest a double case design. Outer white...

kanewolf

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Greetings,

I am a chemist inquiring on how to build a submergible underwater computer and just had a few questions regarding such. The computer needs to be put into a cylindrical case that is 12 by 4 inches in diameter so I plan on using a Pico-ITX motherboard but was curious if i wanted to go fanless with this build what would be the best processor for moderate to even low end processing power but has a very low TDP and wouldn't output that much heat. The environment (the water) in this scenario would be helping to cool the server so it wouldn't need to be the lowest TDP processor out there, just a lower end one that still can provide some punch. If there is anyone who can that would be fantastic! Thank you so much.

Sincerely,

Harrison
Are you custom building mounts for this motherboard? If so, then custom make heatsinks which will contact the cylinder to keep everything cool.
 

Atevoh

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Are you custom building mounts for this motherboard? If so, then custom make heatsinks which will contact the cylinder to keep everything cool.
Hello! yes as I can't find anything commercially available in terms of a cylindrical case I am planning on making the case from scratch as well as the mounting. When you say "come in contact with the cylinder" do you mean on the inside or outside?
 

kanewolf

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Hello! yes as I can't find anything commercially available in terms of a cylindrical case I am planning on making the case from scratch as well as the mounting. When you say "come in contact with the cylinder" do you mean on the inside or outside?
Look at the commercial cases for PI4s -- https://www.tomshardware.com/news/akasa-release-a-gem-of-a-raspberry-pi-4-case They come with a heatsink that goes between the hot components and the INSIDE of the case. Thereby making the case a heatsink. With an infinite heatsink of a large volume of water, you could use any CPU you want. How is power and data for this device being connected ?
 

Atevoh

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Look at the commercial cases for PI4s -- https://www.tomshardware.com/news/akasa-release-a-gem-of-a-raspberry-pi-4-case They come with a heatsink that goes between the hot components and the INSIDE of the case. Thereby making the case a heatsink. With an infinite heatsink of a large volume of water, you could use any CPU you want. How is power and data for this device being connected ?
I was just going to ask if there were any power supply options, i was looking at the smallest form factor PSUs on the market rn (or what I have seen so far), the SFX line, but unfortunately they measure too tall by exactly an inch. The form factor of the cylinder needs to be precisely 12 by 4 inches. That is currently my task, to find a power supply that will work. If that doesn't work I have contact with someone who may be able to help me with the power difficulties, as in doing a complete DIY power system, I don't know any specifics on how that would work. As far as data i was thinking something like a SSD for its small form factor and then just building a place to mount it when i make the whole mounting system.
 

kanewolf

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I was just going to ask if there were any power supply options, i was looking at the smallest form factor PSUs on the market rn (or what I have seen so far), the SFX line, but unfortunately they measure too tall by exactly an inch. The form factor of the cylinder needs to be precisely 12 by 4 inches. That is currently my task, to find a power supply that will work. If that doesn't work I have contact with someone who may be able to help me with the power difficulties, as in doing a complete DIY power system, I don't know any specifics on how that would work. As far as data i was thinking something like a SSD for its small form factor and then just building a place to mount it when i make the whole mounting system.
Why not do DC external power? Then you use a DC to DC converter -- https://www.mini-box.com/DC-DC
 

Atevoh

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This thread makes me want to go dunk my phone in the tub and see if I can still connect to WiFi and Bluetooth...lol
It's usually done under mineral oil. DI water could be used but it's very aggressive with free ions.
This build is going to need to be under salt water conditions in the ocean, i'm kind of throwing out all classical building techniques with this one. It is going to be almost all DIY, just trying to get an understanding for the possibilities out there and to see if i can use anything already available to me.
 

kanewolf

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We are going to start with a depth of just a meter or two, but eventually (with an improved design) have it up to depths of 10 meters.
1 or 2 meters is ip68 waterproof depth. So an ip68 rated ethernet or power cable entry should be OK. 10m exceeds IP68 (and technically it is fresh water).

Why DC to DC ? Simplicity. Can be battery/solar powered. Lower voltages for input to the system.
 
We are going to start with a depth of just a meter or two, but eventually (with an improved design) have it up to depths of 10 meters.
What plans have you made for the pressures involved? Have you taken the total surface area of your cylinder into account here? PSI refers to only a SINGLE square inch. Unless your cylinder is the size of a thimble you're looking at quite a bit more than that. You'll need to take into account penetrations (for cables and such) as well. At 44PSI per 100ft you're looking at ~15PSI at 10 meters. You'll want to plan for 20 just for a safety margin.
 

punkncat

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Is there some specific reason you couldn't go with a miniature computer, NUC inside your custom made enclosure?
Have you considered how you are going to get I/O interface for the humans using it, or is everything going on underwater going to be strictly sensor based input (logging so to speak)?

I am having a hard time understanding what the requirement for the computer to be "underwater" when anything you could possibly need to do could be a remote cable device/sensor w/e, recorded, so forth.
 

Atevoh

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What plans have you made for the pressures involved? Have you taken the total surface area of your cylinder into account here? PSI refers to only a SINGLE square inch. Unless your cylinder is the size of a thimble you're looking at quite a bit more than that. You'll need to take into account penetrations (for cables and such) as well. At 44PSI per 100ft you're looking at ~15PSI at 10 meters. You'll want to plan for 20 just for a safety margin.
I'm working with my father and he has designed numerous underwater solar UAVs that are cylindrical and capable of depths far beyond the 10 meter range, i do not know the specifics but i know that he has pressure handled in this case.
 

Atevoh

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Is there some specific reason you couldn't go with a miniature computer, NUC inside your custom made enclosure?
Have you considered how you are going to get I/O interface for the humans using it, or is everything going on underwater going to be strictly sensor based input (logging so to speak)?

I am having a hard time understanding what the requirement for the computer to be "underwater" when anything you could possibly need to do could be a remote cable device/sensor w/e, recorded, so forth.
The server we are building at this very moment is more of a mock up, we are just trying to find a way to have a server underwater, starting out with a classical one then move to almost an entirely "built by ourselves" datacenter. We are trying to use as little pre built things as possible.
 

Atevoh

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Can I ask WHY it has to be a cylinder? Pressure won't be an issue at 10m or less.

I would recommend you mock up everything in PVC before going to aluminum (assuming your deployed cylinder is aluminum).
So i was mistaken and we are gonna be going up to depths of 30 meters eventually, so that is why it must be a cylinder.
 

punkncat

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What advantage are you trying to realize by having the "server" be both that small, as well as having to face the challenge of the actual computer being under water? What problem is being solved? What solution is this "innovation" offering?

I cannot say I am "read up" about it, but have seen a few articles eluding to Amazon utilizing floating server centers. I don't know if searching that rabbit hole would offer any insight for what you are trying to achieve or not.
 
I'm working with my father and he has designed numerous underwater solar UAVs that are cylindrical and capable of depths far beyond the 10 meter range, i do not know the specifics but i know that he has pressure handled in this case.
If he has done this previously then he knows that a sphere is the ideal shape for this. A cylinder requires extra bracing along its entire length (look up submarine design). And, as others have asked, what, exactly are you trying to accomplish here? There are FAR better ways to cool a computer.
 

Karadjgne

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Temps will vary. Something used in the upper 2m or so surface area (especially in tropical regions) is going to have a much harder time dissipating heat. Start dropping down and temperature gradients will solve all that, at 30m you'd not need a heatsink for a directly connected 10900k overclocked to the moon.

The motherboard itself and any storage are going to be the issue in warmer waters as the case itself will not transfer much heat when there's little temp difference inside to outside. Fans won't help because of the enclosure, 72°C air is still 72°C whether it's moving or not.

Watertight fittings aren't an issue, it's the same theory behind a wired AV, just different cables.

I'd suggest a double case design. Outer white fiberglass/PVC shell that's non-water tight, and an inner aluminium pressure cell. Works on the same principle as a wetsuit, allows water to surround the inner shell, but prevents sunlight from actively heating up the shell at moderate-low depths/surface. Small plexi port on the inner shell giving access to a small lcd screen for OS use. Heatsink being a direct connection from cpu IHS to aluminium shell.
 
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Atevoh

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Aug 19, 2016
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What advantage are you trying to realize by having the "server" be both that small, as well as having to face the challenge of the actual computer being under water? What problem is being solved? What solution is this "innovation" offering?

I cannot say I am "read up" about it, but have seen a few articles eluding to Amazon utilizing floating server centers. I don't know if searching that rabbit hole would offer any insight for what you are trying to achieve or not.
What we are doing is similar to Project "Natick" by Microsoft, except what we are doing is on a much smaller level. Our plan is different in a way I cannot divulge unfortunately, but what we are doing is something that requires the build to be this size and layout.
 
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Atevoh

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Aug 19, 2016
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If he has done this previously then he knows that a sphere is the ideal shape for this. A cylinder requires extra bracing along its entire length (look up submarine design). And, as others have asked, what, exactly are you trying to accomplish here? There are FAR better ways to cool a computer.
Yes we are aware that there are better ways to cool a computer, we are doing something to Project "Natick" which is one of Microsoft's main underwater server projects. What we are trying to do though is at the individual level though, and we will eventually be using a different technology to them. I'm sorry i can not tell you exactly what we are doing but the way we have it set up to be is the way it needs to be.
 
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