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Liquid Cooling More than One Component?
static0verdrive asks: "I am new to liquid-cooling, and I have designed a system for use in a micro-ATX OpenBSD server, with the following layout: Fillport > Reservoir/Pump > Y Split (one to CPU and the other to chip-set) > Y Reconnect > Radiator/Fan > Back to the fillport. I don't like the idea of having the hot coolant coming from the CPU going directly to the chip-set, hence the Y split. Could this split cause any problems? Would there be a difference in pressure (considering the CPU is most likely a lot hotter) that could cause an issue? How would you handle liquid-cooling more than one component? What if I wanted to cool 3 components, such as in the case where I add a video card to this setup later on?"
Jean Gallier at UPenn has a lot of stuff about this on his webpage: here
I think the idea is potentially suspect because you have no guarantee that both sections of the split line will have equivalent flow resistance. if one is more resistant than the other, more of your flow will go to the path of least resistance. It seems overkill to liquid cool the chipset's core chip. I'd suggest doing a series connection, cool water going to the chipset then CPU because its heat output should be much smaller than the CPU.
As a Slashdot user
Just my $0.02.
ttuttle is a rankmaniac
Dude, just throw it in a swimming pool ... and go out and buy a Mac.
I've looked into liquid cooling for a machine, but haven't done anything yet. From what I've found out, an ideal solution is to go reservoir->pump->cpu->video card (if doing video card)->north bridge-> radiator->reservoir. You get max cooling this way. Introducing a Y splitter introduces another connection (in which liquid can leak) and split forces of liquid. The liquid will take the path of least resistance, so you might not get max colling that way. I've found that Systemcooling.com has a wealth of information. You might want to pose this question on their forums, as they do more liquid cooling and have people who have done many systems.
You can find some really good advice and watercooling guides, like this one: http://forums.bit-tech.net/showthread.php?t=99891.
The bottom line on your waterloop, in my own experience, you'll find that the order in which the water is flowing results in negligible water temperature increase/decrease.
I have two machines WC'ed, a P4 (pre-prescott) and a Dual Xeon. The order of the loop for the P4, pump/res> radiator > CPU Waterblock > GPU Waterblock > Flow Indicator > Pump.
The P4 only gets to about 90F during heavy gaming sessions (ATI X800XL). Then again, I have a triple 80MM fan radiator. Your results may and will vary.
having a good single chip water cooling system and moving to a dual chip (each being a dual core opteron) I had somewhat the same quetion.
I previously cooled my cpu and graphics card (both 25% overclocked) but because of an initial lack of funding went back to air cooled and
modest (10%) overclock.
Anyone tackled with with a single pump/radiator solution?
thanks!
Unix, an obscure operating system developed by bored researchers in an attempt to get a better game playing experience.
http://stringed.org/images/DSCF0006.JPG
out to cpu, split one into geforce 6800 ultra OC, meet up with the split 1/4 " pipes to go back into the reservoir. works beautifully... in a non-airconditioned room in muggy SE Pennsylvania playing the Prey demo... only got to 42 Celcius. Add AC and it maxes out at 39 Celcius.
It's a Koolance rig.
My name is Wootzor von Leetenhaxor
Don't use "Y-splits" to redirect fluid. I understand your concern that you don't want hot parts connected in series but a series connection is superior to a parallel setup. The resistance overhead for a series setup is negligible. Also, was previously mentioned, it is more advantageous for you to minimize the amount of junctions and thereby increase the reliability of your setup.
"I am new to liquid-cooling, and I have designed a system for use in a micro-ATX OpenBSD server, with the following layout: Fillport > Reservoir/Pump > Y Split (one to CPU and the other to chip-set) > Y Reconnect > Radiator/Fan > Back to the fillport. I don't like the idea of having the hot coolant coming from the CPU going directly to the chip-set, hence the Y split. Could this split cause any problems? Would there be a difference in pressure (considering the CPU is most likely a lot hotter) that could cause an issue? How would you handle liquid-cooling more than one component? What if I wanted to cool 3 components, such as in the case where I add a video card to this setup later on?"
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Splitting the main(Y-split) to cool several devices is generally not recommend over cooling multiple components in serial.
Most people go: Pump->CPU->radiator->reservoir
some people go: Pump->CPU->Video GPU->radiator->reservoir
and very few people go: Pump->CPU->Video GPU->Chipset->radiator->reservoir
( or even Pump->CPU->Video GPU #1>-Video GPU #2->Chipset->Memory->radiator->reservoir)
As you add more and more stuff to the circuit, you'll also need a bigger pump, a bigger radiator, and you'll have to seal the connection points more carefully to gaurd against leaks resulting from higher pressure. It's the general consensus that splitting the coolant in a parallel fashion like you're describing is less effective than connecting the components in serial. The primary reason is that flowrate X volume is king in water cooling...with a Y-split you're cutting your CPU water cooling volume in half, and probably restricting flow even further with narrower tubing. Also, pressure drop in the system is a function of how much tubing you use. More tube, less pressure. People have tried this before...and their results weren't comparable with serial.
I'm assuming you want to water cool so you can overclock. If this is so, then you need to prioritize your CPU over everything else. If you don't plan on overclocking and just want the silence, then you're still better off using serial because it's cheaper and safer(less connection points means a lower leak probability).
Don't worry about warm water returning from the CPU and 'heating' the chipset. Fast flowrate and the high heat capacity of water keep this from being a problem. Generally the water temperature across the entire circuit is nearly homogenous(maybe 1-2 degrees difference).
To learn more:
1) Goto http://www.ocforums.com/forumdisplay.php?s=099a5c
2) Spend at least 2 hours reading the stickies etc. (or register and ask your own question, the folks there are very knowledgeable.)
Good luck with it!
The government has a defect: it's potentially democratic. Corporations have no defect: they're pure tyrannies. -Chomsky
Why not just use a smaller diameter tube for the components that don't need as much cooling? KISS
Just as an aside, this is kind of a neat example of the resistors-in-parallel theorem; if you equate pressure to voltage and electrical resistance to flow resistance, and current to flow rate in volume/time, I'd be very surprised if you didn't get a result where the flow through each cooling block was close to what you'd calculate by dividing the pressure drop across the block by the flow resistance through the same block.
The reason I bring this up is that it gives you a nice way to easily calculate the flow resistance if you only have one flowmeter (if the manufacturer doesn't state it): you can connect up each of the blocks separately and figure out their "resistance" by measuring the flow (for safety I'd want to check it at various pressures / flow rates to see if it's linear) and then use that value when figuring out the flow with both blocks in the system in parallel.
If you also knew what the flow resistance was of the tubing (this can also be obtained from a lot of engineering manuals), it might be possible to equalize the flow through both blocks by adding extra tubing to one or the other, twisting it in a spiral, etc.
There are obviously going to be some problems when doing it this way -- it's a big approximation to just assume that a liquid is going to flow like electricity (as you change the pressure and flow dramatically you might enter different flow behavior regions, i.e. non-laminar, and it might change unpredictably), but it would be easy enough to try if you had one flowmeter and pressure gauge.
"Ladies and gentlemen, my killbot features Lotus Notes and a machine gun. It is the finest available."
Some people want to water-cool in order to cut down on fan noise.
Rather than overclocking, they want to take a regular desktop processor running at its normal speed and move the heat out of the case and into a large radiator, where it can cool just into the ambient room air, without fans.
I don't know how well this works, or how much noise the pumps make, but I've definitely heard people talking about using liquid systems as an alternative to forced air on basically typical (non-hotrodded) desktop systems.
"Ladies and gentlemen, my killbot features Lotus Notes and a machine gun. It is the finest available."
Don't want to beat a dead horse, but to reiterate some of the other comments, the series loop would be the best idea if you only have a single pump/resivoire. With a larger radiator and higher capacity, more coolant will be cooled before entering back into the chain of blocks. With a single series circuit moving coolant quickly, just as much heat will be transfered without the coolant temperature increasing as much, thus making temperatures at successive water blocks negligeable to cooling performance.
On the other hand, splitting the flow into parallel paths decreases flow through the blocks that come after the split, causing the coolant to reach higher temperature, and ultimately demanding more work from the radiator.
..maybe check out HP's new air cooling rig instead.
hi. I'm a mechanical engineer (who loves to tinker) and has used watercooling. I'm going to suggest a few steps to help you see that your system is successful. (I'm not going to use any numbers or calculation, because I'm very lazy: 1) I did the work once for my own systems and found that the work was overkill, 2) water can carry more heat than you realize 3) I'm lazy.
...And that I'm lazy?
1. Relax, be lazy and have a beer. You're dealing with (I think) a server in your home that is probably going to remain lightly loaded. Even if you expect heavy loading, you still need to relax.
2. Please know that the major reason to use water is that water has a MUCH higher heat capacity than does air. Another good reason is that water conducts heat better than does air.
3. What you've already done is probably good enough. I use one water pump and four manifolds to feed three systems. (The water pump has a simple backup, although this is manual for now. I've not taken the time I need to learn how to design my vision of a good backup for it.) I don't overclock, but I'm lazy and don't want to deal with the hassle.
4. You're talking about pulling from the system a maximum of probably 150 watts, assuming that your mATX system has a VERY high load on it. Unless you live in the midst of the mojave, you won't have any trouble pulling sufficient heat from the system. Remember that your car's cooling system can remove MUCH more heat. (A note to the pedantists: SHUT UP. I know that there are differences and I'm inimately familiar with the differences, but the analogy is good. Based on the scant information the poster has given, he's already well-covered.)
5. TEST IT. Stop worrying, turn it on and see what you get. If you don't (as I don't) want to bother with lmsensors, (or the BSD equivalent), turn it on, load it for a few hours, reboot it and see what the BIOS tells you the temperatures are. If everything looks good, then you're golden. This is not a good design/testing methodology, but you're not designing a nuclear reactor which needs perfect redundancy and endless, constant tests to ensure that everything is operating perfectly. Keep an occasional eye on your water pump (there are several different types of flow meters available) and a very lax eye on temperatures; doing both of these will keep you sufficiently covered. (By the way, your sytem will still probably circulate a very small amount of water even if the pump fails. This depends on a temperature and gradient difference, though.)
p.s. I'm assuming that you're not overclocking your system, nor operating in extreme environments.
p.p.s. There are sizable holes in my advice. If you're looking for specific numbers, I'll charge you reasonable fees for reasonable consultation. Feel free to contact me if you want to pay my inflated rates.
p.p.p.s. Have you noticed yet that I like bullets of one kind or another?
my last little bit: my point 5 is probably the best of what I've said. Turn it on and see what you get. Edison didn't have any results until he provided current. If you turn the thing on and it doesn't work out well, you can turn it back off in a few minutes and probably still be just fine. Remember, though, that most BIOSs can be configured to shut down the system if the temperatures get too high, providing enough fail-safe to determine that everything works.
As a Slashdot user (who knows nothing about liquid cooling), it seems to me like the way to ensure each component gets adequate cooling is to have a big, shared radiator and a smaller, separate pump for each component. That way they are each ensured their own coolant flow. The downside, of course, is that you need three pumps, which will cost more and make more noise.
Just my $0.02.
ttuttle is a rankmaniac
Reason 1:
Your lower water flow in each cold-plate due to splitting the flow with a Y lowers the velocity thru each cold-plate and thus lowers the heat transfer between the water and the cold-plate.
Reason 2:
You do not have the equipment needed to measure the flow thru the 2 branches of the Y so you risk having 1 component be hotter than needed and not know it. Some will suggest using valves to choke flow to the higher-flowing cold-plate, but this way you are wasting pump head.
Sadly, water cooling has come from being done right (like by IBM and the water cooled version of the VAX 9000, which was changed to air cooling before being shipped) to the use of feeble pumps and undersized radiators. In many cases, water cooling in PCs has become the equivalent of a "Type R" sticker on a Honda sedan.
There is nothing magical about water cooling. An air cooled setup can have the same performance, given good heat sink surface area, good fin efficiency of the heatsink, and 600 feet/minute airflow. A water cooling setup CAN let you to increase the effective heatsink area for ejecting heat into the room air without a fin efficiency penalty. But to do this you need enough flow and enough radiator area, and to keep costs down most kits are marginal on both.
It shouldn't matter, but if you're that worried about your chipset temps you could throw another 80mm rad in between the proc and northbridge. Plenty of people i know though run everything on one loop with only 1 large rad or just an aditional one between the proc and graphics card(s).
"Sic Semper Tyrannosaurus Rex."
Not really... I'm planning a machine that'll have 10 hard drives and 2 CPUs in a (slightly larger than normal) tower case. Getting all that heat out without either watercooling or hooking it up to a leafblower is going to be difficult. If I don't get the heat out, poof go the hard drives, and with them all my lovely photos.
Yes, the drives are RAIDed, and yes I have backups, but who wants to re-build or restore a 2TB archive.
A parallel tubing configuration will always be superior to a series configuration (unless you are using a positive displacement pump for some reason). IF you have a method to balance the flow correctly to each component (such as throttle valves). The reduced flow resistance will allow the pump to operate at a higher flowrate and will make heat transfer in the radiator more efficient. This will reduce the outlet temperature of the radiator, supplying cooler water to each component. This makes all your components run cooler and also reduces the power usage of the pump.
If you don't have a method to correctly balance the flow then your best bet is a hybrid series-parallel configuration. The best solution will depend on the heat load of every component you want to cool and the physical characteristics of the pump and radiator.
My current loop is as follows:
Athlon MP2800+ -> Athlon MP2800+ -> AMD 762 Northbridge -> FireGL X1-128 -> Koolance 2 DIMM RAM cooler-> Reserator.
Once the temperatures reach steady state, the difference in temperature between any two points in the loop is less than 2 degrees C. In doesn't really matter how much water is circulating or how fast (these do matter though, in determining how fast the steady state can change when a cooled component suddenly changes its temperature). What really matters is the surface area of your radiator, and the airflow over it's fins.
Under full load, on a 30C day, the Reserator is very warm to the touch. I can drop the temperature to below room temperature by putting a fan behind it. Whatever temperature the radiator is at is the temperature the blocks are at (at steady state conditions).
If you want to cool more components, you don't have to fill up your case with parallel cooling loops. Instead, add them in series and add another radiator is series also. You only ever need one input hose and one output hose piercing the case. The Reserators work really well for this, since you only need a pump in one of them. The other(s) are just extra surface area.
A republic cannot succeed till it contains a certain body of men imbued with the principles of justice and honour.
Actually, pissant, it's going in a closet next to my bed. It will have no airflow, and I want it silent while I sleep.
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thanks for linking us to the front page of the university... terribly helpful.
Mark of the Coder fades from you. You perform Opening on World of Warcraft. Warcraft crits GPA for 4. GPA dies.
http://www.markusleonhardt.de/en/oelrechner.html
The idea is to submerge the entire computer in vegetable (or better, mineral) oil. This cools ALL components at a lot less cost than a bunch of watercool components, and at less effort as well.
Mark of the Coder fades from you. You perform Opening on World of Warcraft. Warcraft crits GPA for 4. GPA dies.
OpenBSD is an operating system. You don't need to hunt down and install random stuff to try to build an OS on top of it like with linux. He can just do sysctl hw to see his temp/volt/etc.
I drilled a couple holes each in the CPU and chipset to improve water flow. Hooked them up with a Y split to an old VW Beetle radiator. Works like a charm. Never goes over room temp.
please excuse my apathy
I've seen that done as an experiment, and it's always intrigued me, but I've wondered if anyone has actually used such a system in anything approaching production. Even if "production" was 'average everyday home use.'
I'm curious as well whether the heat transfer from a chip submerged in fluid like that is better or worse than one that has a cooling block with some sort of coolant forced through it. The dissipation of heat throughout a static volume of fluid might end up being worse than you can achieve by forcing coolant through pipes, because of the hot spots that would develop in a tank. (You could prevent this by circulating the fluid in the tank.)
Submerged-liquid cooling is one of those ideas that keeps coming up, and it's obviously possible to do, but it's never really taken off as more than an experimental thing, even though it would seem on the surface to be much easier to do than running pipes and cooling blocks and radiators and the rest of the stuff that's involved in a "conventional" setup. Given that it ought to be that much easier, and nobody seems to use it, I'm suspicious.
"Ladies and gentlemen, my killbot features Lotus Notes and a machine gun. It is the finest available."
Of course, the liquid is about $270 a liter.
It must have been something you assimilated. . . .
Also, note that if you are doing this as the OP suggests (cron job, etc), there is a *nix utility out there that can turn on/off individual parallel port pins - I don't have a link, but it is fairly easy to find (search under parallel port interfacing off of the ePanorama site). The only possible 'catch' to the app is that it needs to run as root, but I would imagine you would set up the cron job and such for this kind of monitoring that way anyhow...
Reason is the Path to God - Anon
Jean Gallier's Home Page
Worth checking out, he has made some of his books downloadable if anyone is interested.