The Neophyte's Custom Liquid Cooling Guide: How To, Why To, What To Expect
by Dustin Sklavos on September 30, 2013 12:01 AM ESTObviously there's a tremendous amount of information to sift through. This is without a doubt the longest article I've ever personally written; normally I leave the comprehensive works to my more gifted colleagues. I couldn't resist the challenge or the opportunities that presented themselves, though. Even as I write this, I'm testing an engineering sample i7-4770K donated by iBuyPower and finding it to be an infinitely more capable performer than the original retail chip I used. That's not a black mark on CyberPowerPC; it's not like they deliberately sent me a bad chip. It's more a reflection of the chip lottery that is a fact of life for enthusiasts.
Whether or not a custom liquid cooling loop is worth the time, effort, and expense is really going to be a matter of opinion for each individual. As someone who likes working with his hands in general, there was a lot of appeal in just building something, and a tremendous amount of satisfaction when, performance metrics be damned, the thing worked. When that pump fires up and you hear that coolant start circulating, and then after you've filled up the system just seeing the coolant cycle...that's rewarding. This is something that a lot of people have accomplished, sure, but it's much more work than just assembling a computer and sticking a CLC on the processor.
Performance wise, if you're trying to get a better overclock on the CPU, I think we're at the point where a good closed loop cooler is probably going to be enough. Dumping boatloads of voltage into it just to get incrementally higher performance past the chip's inflection point doesn't really do you any favors long term, so any increased thermal headroom a loop can offer you is somewhat negated.
Where I think watercooling really shines is when you apply it to graphics cards. High end graphics cards are ripe for it, with air coolers that are already being pushed fairly hard. Watercooling tanks the temperatures on those, and if you're feeling adventurous, can theoretically allow you some room to play with voltage and get a healthier bump in performance. I think it's worth it just for the low thermals and substantially reduced noise, personally, but if you're looking to sandwich two or more cards together, it's also nice not to have to worry about suffocating air coolers.
Finally, it's important to accept the limitations on the hardware you have. Chip lottery means that watercooling may just not give up the performance you were hoping for. It's often said that there are no guarantees when it comes to overclocking, but in the backs of all of our minds, with each generation of hardware, what we really want to know is "what's the typical overclock." What we really think is that we can count on the "typical overclock," but that's not true, and hopefully my experience here demonstrates that. Ian has an i7-4770K in his lab that won't go any higher than 4.2GHz for love or money. Overclocking is always going to be a gamble.
There are no clear recommendations that I can offer at the end of this experience; the best I can do is present you with the information and my experience and let you decide for yourself. I will say that Swiftech in particular has been tremendously helpful, overnighting me parts when I made mistakes and being exceptionally patient in answering any questions I had so that I could pass that information along to you. With a system like this on hand, it's difficult not to want to experiment and play in this new space, so expect at least an update or two with what I've done and tried and with more information in the future.
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Sadrak85 - Monday, September 30, 2013 - link
And one more thing is the addition of onboard voltage regulation, which is a lossy process almost by definition. Meaning, even with the better TIM, I seriously have my doubts that the thermals could hit the level of IVB or SB. Unless Intel somehow has some magic way of using the voltage and amperage they're scrubbing off.*small note, a good motherboard input, in terms of electricity, would pass through the filters pretty cleanly, but because Intel sets the specifications for the input, I have my doubts that they require such a thing, since the feature they added to their chip was to save money for the motherboard vendor.
leafonwind - Monday, September 30, 2013 - link
The thermal interface material is minor compared to the interface distance. Thermal resistance is L/kA. Going from a millimeter of thermal paste to an 10 micron gap (typical of paste when applied correctly) will give a 50x improvement. The difference in k between a good thermal paste and a bad thermal paste is typically a 5x difference unless you get into exotic materials like cadmium. http://forums.anandtech.com/showthread.php?t=22618...gandergray - Tuesday, October 1, 2013 - link
To bolster Von's point, see the work performed by Idontcare: http://forums.anandtech.com/showpost.php?p=3405318... .merikafyeah - Monday, September 30, 2013 - link
Super tiny correction: While it is true that liquids draw away heat much better than air, one must be cautious not to mistake water as a good CONDUCTOR of heat, aka something that "transfers" heat very well. Water is in fact an INSULATOR of heat, aka something that "absorbs" heat very well.merikafyeah - Monday, September 30, 2013 - link
Note wording on first page, third paragraph.ShieTar - Monday, September 30, 2013 - link
Correct, but to be precise, neither air nor water will conduct heat quickly enough for PC cooling purposes, both are only used to absorb the heat before being transported away from the heat source.Which makes you wonder how a closed-loop, compressed air cooling system would fare against a water-cooling system. Heat capacity might still be lower for air than for water, even at increased pressures, but I assume that you can produce higher flow rates for a compressed gas than for a liquid. And you could use the required compressor in order to:
1) Reduce the air temperature below room temperature before sending it to the heat sources.
2) Increase radiator temperature over the CPU/GPU temperatures, thus achieving the same heat transfer with lower air flow rates through the radiator. Though temperatures above 100°C may be unsafe in a consumer device for several reasons.
Does anybody know if such a system has been considered and tested anywhere?
Death666Angel - Monday, September 30, 2013 - link
Considered? Probably. Used? Not to my knowledge. If you have a compressor it makes more sense to cool the water used in the loop to just above freezing or even below freezing with the right additives. Of course, if you cool it that much, you have to worry about condensation, so most people I read about who use compressor cooling for their liquid (instead of large radiators) keep the water around room temperature and have the cooler in another room, to not be bothered by the noise.The stuff that is used to conduct heat away from the components inside the PC is the metal heatsink. In the case of pure air cooling you then push air through the metal heatsink fins. Because of the delta T you have the air warming up, the metal cooling and being able to absorb heat from the CPU/GPU etc. again. In case of water cooling, you have the water running through the heatsink (usually some very fine canals inside that increase surface and flow rate) which absorbs the heat from the heatsink and gets transported to (large) radiators where air is again pushed/pulled through the radiator fins in order to cool it.
Sadrak85 - Monday, September 30, 2013 - link
Used all the time; Nitrogen is the most common component of air; it is compressed so much as to become a liquid. Then, thanks to the Carnot cycle, cooling the liquid to room temperature results in it boiling and becoming ultra-cold air, which cools a processor.A similar thing happens with your refrigerator.
These coolers, however, require massive power to get them to that level, so they're only really useful for very niche-applications, but the equipment isn't really that hard to find. An evaporator will cost you something like $200 to $300, and then the Nitrogen.
Now, if you're talking about keeping the air gaseous, then what you'll find is it just isn't possible. Cooling it very much with pressure on it will result in it condensing to liquid. If you just compress it, without the cooling, you'll heat it up, of course, which is how your diesel engine works.
ShieTar - Monday, September 30, 2013 - link
Fair enough. I am fully aware of the cooling concept via liquid nitrogen boiling itself, but I was considering a much simpler concept. Maybe I should describe it in a bit more detail.Imagine a closed air (or just nitrogen) system where the air pressure is about 3 bar within a radiator and about 2 bar when it circulates within the cooling blocks. You can have temperatures around 200K at 2 bar without liquifying, and not that much higher at 3 bar.
So you offer your GPU/CPU coolers 2bars of air at 200K, maybe heat it to 220K, compress it to 3bar/330K, cool it back down to 300K (close to room temperature), decompress back to 2bar/200K.
What needs a little more math is, just how much volume of gas do I need for this to transport 600W or so of power by this concept. And how much additional energy do I waste on the compression process. And probably, just how horribly noisy will this setup get with 2bars of air at high velocities getting pressed through the cooling blocks at high velocities.
Yeah, the more I think about it, the worse the whole concept sounds. Nevermind it.
UltraWide - Monday, September 30, 2013 - link
Excellent article, I enjoyed reading this journey into water cooling. Keep up the great work!