Water cooling of 0.5-1 kW processors

[DanRR]

you sound like you don't have any clue how that works. just define a custom fan curve in whatever you use to control the fan speed. for example in the bmc fan control utility ... there you should be able to limit the maximum pwm percentage.

That option exists, but here is one caveat: I spent two weeks trying to connect all different ways to the board with BMC, then called Support and we both failed, something is wrong somewhere. Some day I will return to this but have no patience and time to try right now. Now looking at other possible solutions. Undervolting is potentially one of them and in principle extremely easy doable. I have it for low power fans and it works perfectly

Or if you have experience with electric installations and know what you are doing, you could just cut the 12V and GND lines from the pwm connector, put ferrules on the strands and connect them to a proper 12V PSU (eg MeanWell LRS series) - not that noname "cheap" stuff you posted

That is what I was doing before coming here.
By the way checked MeanWell, it has no single variable voltage PSU, and the problem with constant 12V power and how to get it is not a big deal. Molex was mentioned because we discussed it above and always better to use standard solutions.

 

[DanRR]

if everything fails

get a waterchiller for your waterloop, and peltier plate preferably one you can control with your core temps.
*note if you want to really cool it down, make sure your pipes, chiller are rated for acetone, ethanol - but distilled water as long as you keep it moving shouldn't freeze either even when its below freezing point - depending on temps you need it to move faster which may require more fancy chiller that can handle sub-zero/freezing temps, pumps are typically a problem if you are doing subzero - so you might need to install heating (wire-heaters) on some parts that can't handle those temps - the pump was main failure point years ago when i played with dice/winter waterloop cooling. You will also need to cover everything in vaseline (mobo, components etc), and insulation for cables/pipes.

Thanks for the idea. Any ideas are welcome.
Aside from the vaseline do I correctly understand that for each Watt of heating we will need to spend minimum one Watt for cooling, and actually much more because efficiency coefficient for Peltier coolers is far from 1. So having 2kW system times 10000 hours in a year we will get 20,000 kW*hours per year. With electricity 15 cents /kwH that is $3,000 /year. And with Peltier minimum 6,000 /year. Isn't that chilling us better than Peltier?

 

[nexox]

Peltier efficiency is awful but heat pumps are pretty good, there's a wide range of hardware that each get different efficiency in different conditions but it's certainly possible to get 4-5 times more energy moved than you put in, so you're only looking at probably 500-600W of cooling power, eg a cheap inverter-drive window unit air conditioner.

 

[DanRR]

Peltier efficiency is awful but heat pumps are pretty good, there's a wide range of hardware that each get different efficiency in different conditions but it's certainly possible to get 4-5 times more energy moved than you put in, so you're only looking at probably 500-600W of cooling power, eg a cheap inverter-drive window unit air conditioner.

I thought of that. Do miniature heat pumps exist? I afraid their efficiency is not 4-5 times, which usually takes place for larger system. With micro heat pumps the efficiency could be around 2 only. But for the 1kw standard size heat pumps this indeed can work

 

[nexox]

I thought of that. Do miniature heat pumps exist?

Sure, you can get a countertop ice maker with a heat pump, plus there are various sizes of dehumidifiers and refrigerators which use them, but most of those will require some effort to adapt and the countertop stuff tends to be lower efficiency, if you want cheap and efficient it's very difficult to beat a 600W window unit, which probably has enough fan power to blow cold air right through your radiators.

 

[CyklonDX]

Thanks for the idea. Any ideas are welcome.
Aside from the vaseline do I correctly understand that for each Watt of heating we will need to spend minimum one Watt for cooling, and actually much more because efficiency coefficient for Peltier coolers is far from 1. So having 2kW system times 10000 hours in a year we will get 20,000 kW*hours per year. With electricity 15 cents /kwH that is $3,000 /year. And with Peltier minimum 6,000 /year. Isn't that chilling us better than Peltier?

Use pletier only as stop-gap on spikes, and when you need extra oomph. manage its power draw only when your vrm goes over certain wattage, or if you prefer temp sensor on the die when it goes over certain temp. You don't need to run it at full all the time (i.e. classic approach.)


i.e. for 100W peltier plate
0-5W @ 50'C cpu
10W @ 55'C
25W @ 60'C
60W @ 70'C
80W @ 80'C
100W @ 90'C
(best to use analog wave, to manage how much wattage you pump - not steps, as those might not be fast/accurate enough)

it all depends how much performance you want.
The copper block takes a while to grab that heat away from the cpu - and its either peltier or some cray/submerge 3m/or spray tech to quickly transfer heat away from the die. Chilled water can do a lot - and might be enough for your use - but going to 1kW cpu load, i think you will reach problem of how fast you can transfer that heat away from die (I don't think water block can do it fast enough).

 

[DanRR]

Gentlemen. I present to you, my magnum opus:

The Noctua 120mm NF-a12x25 fan tilt test: a 1.7W puff of air

http://imgur.com/a/fjfYu3k

That is the reason of Noctua showing no differences. It is of different class from all other fans, drains more than twice less power than Arctiv4k and does not create any pressure at all probably

 

[DanRR]

Use pletier only as stop-gap on spikes, and when you need extra oomph.

And what about vaseline ? Will it ruin expensive motherboard and 3 years warranty? Is this design all kinds of faults tolerant?

 

[CyklonDX]

And what about vaseline ? Will it ruin expensive motherboard and 3 years warranty? Is this design all kinds of faults tolerant?

The vaseline is to stop you from getting a short. Stop the condensation of air around components.
A quick wash in dishwasher or hot bath can clean it up.
(fully submerged mobo is another solution.)

// condensation happens when you have a big difference between temps, and air is slow enough for air water molecules to condensate - cranking up fans can only do so much, and you can't blow air into every crevice of the board or/and under the chip connecting pads/legs.


Electricity price wise, immersion build might be better. You just need to seal the case air tight / have it in aquarium or something; have a condenser (i.e. a metal rod that is cold enough to condense the liquid).
You want to use liquid with low boiling point, and quick condensing point. Fluorine is great as its non-corrosive, there are also fluorine based liquids like HCFC-225 ca/cb. *(but likely more expensive, since they have lower boiling point o 54'C.)

// Note: if one had build SMR or vapor chamber with such fluid they could increase the efficiency or size required to generate power or transfer the heat by many times. *(currently SMR's and vapor chambers use de-ionized water)

 

[DanRR]

Gentlemen. I present to you, my magnum opus:

And finally... (I literally had to move to a bigger power supply)
The uncontested king of suck. The one, The only...
Arctic 120mm 8k tilt test: A WHOLE LOT ----> A WHOLE LOT MOAR

What the heck is that ? Their spec shows that 8K consumes 15W. Lie ?

 

[nexox]

What the heck is that ? Their spec shows that 8K consumes 15W. Lie ?
View attachment 46169

That's not at full speed, if you look at the next paragraph or two on the arctic website (probably not amazon,) it explains:

"Test Setup
Fan on Freezer 4U heat sink on 500 W heating element; fan speed set so that the temperature of the heating element is constantly 20 °C above the ambient temperature."

So it can apparently achieve that cooling performance at relatively low RPM, though the chart is still garbage because it doesn't put 0 on the power axis.

 

[DanRR]

That's not at full speed

Not full speed power consumption, not showing axis at zero all that were dirty tricks to lure busy buyers. The fan is excellent though. Substituting just one single fan with Arctic 8K in Silverstone waterloop gave better performance than give three Arctic 4K. And with the same pretty low level of noise except the first minute at computer boot when it tries to compete with the Musk rocket

 

[TrashMaster]

According to the Arctic webpage specs: Current | Voltage => 2.2 A | 12.0 V DC

So call that 30W at full power which isn't too far off under "optimal" conditions. The larger power supply probably contributes to the power draw a few watts as well.

When you increase friction on a motor however it will suck more power and produce more heat.

 

[nexox]

Not full speed power consumption, not showing axis at zero all that were dirty tricks to lure busy buyers.

On the other hand, I haven't seen any other fan maker even try to advertise efficiency with an actual test setup like that, which is kind of nice, on the other other hand I bet the comparison fans mostly just have a higher minimum RPM and they're cooling the test load further than the stated 20 degrees above ambient, plus they probably tested several different coolers to see which one had the most beneficial flow/static pressure for their fan, etc.

Still, despite their marketing department employing marketing people, I do like their 38mm fans.

 

[DanRR]

On the other hand, I haven't seen any other fan maker even try to advertise efficiency with an actual test setup like that, which is kind of nice, on the other other hand I bet the comparison fans mostly just have a higher minimum RPM and they're cooling the test load further than the stated 20 degrees above ambient, plus they probably tested several different coolers to see which one had the most beneficial flow/static pressure for their fan, etc.

Still, despite their marketing department employing marketing people, I do like their 38mm fans.

To trick people even more, or they failed at math, their marketing people placed 14W at the beginning of axis when it should be 16

 

[DanRR]

Any suggestions for the good fan and a pipe from the window to the waterloop radiators ? I have two tabletop fans staying on the window and blowing air does not matter either out or in of the room, and they fail miserably to cool the temperature in the small room if door is closed. The temperature rises to 40C even at winter (and that was even with Genoas not more power hungry Turins). What will be during summer time I even afraid to imagine

 

[DanRR]

Would be of course great to use 2kW wasted for heating during winter but the system fumes smell like in a paint departments or chemical factory. Initially it was even impossible to stay near computer for a long. Could be this was either motherboard or Samsung RDRAM made in Vietnam or the numerous fans or something else. Right now this is almost not noticeable but after 2-3 hours nearby you still get a headache. Are server people familiar with this electronics equipment smell?

 

[DanRR]

According to the Arctic webpage specs: Current | Voltage => 2.2 A | 12.0 V DC

So call that 30W at full power which isn't too far off under "optimal" conditions. The larger power supply probably contributes to the power draw a few watts as well.

When you increase friction on a motor however it will suck more power and produce more heat.

Many thanks for the excellent suggestions TrashMaster, you are truly The Master

 

[nexox]

Any suggestions for the good fan and a pipe from the window to the waterloop radiators ? I have two tabletop fans staying on the window and blowing air does not matter either out or in of the room, and they fail miserably to cool the temperature in the small room if door is closed. The temperature rises to 40C even at winter (and that was even with Genoas not more power hungry Turins). What will be during summer time I even afraid to imagine

Sounds more and more like you need an air conditioner, if not a window unit then maybe one of those free-standing units with ducts (make sure it has two ducts,) routed to the window, then the cold side near your system. The smell is probably best handled with an activated carbon filter and yet another fan, either a standard home goods type appliance or build your own from components intended for indoor growing of certain odorous plants.

 

[DanRR]

Sounds more and more like you need an air conditioner, if not a window unit then maybe one of those free-standing units with ducts (make sure it has two ducts,) routed to the window, then the cold side near your system. The smell is probably best handled with an activated carbon filter and yet another fan, either a standard home goods type appliance or build your own from components intended for indoor growing of certain odorous plants.

Looks like I am screwed. It is necessary to install large power and price mini-split as all that floor standing air conditioners are extremely low efficient even new. I had one, it was useless. In a year its already low efficiency drops even more and it will consume 1W per 1W heat removed. Doubling the price for electricity I estimated from $3k to $6k a year . They would be easy to install them, you are right, but I do not know what the hell with them, even window airconditioners are twice more efficient. Now I understand why big boys make their own power plants for their data centers