Obviously 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.

Heat, Noise, and Power Consumption
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  • hot120 - Monday, September 30, 2013 - link

    Awesome article!
  • blanarahul - Monday, September 30, 2013 - link

    Hmm.. Can you try cooling those 780s alone? Overclocking the CPU seems pointless on Haswell.
  • valkyrie743 - Monday, September 30, 2013 - link

    overclocking haswell is not pointless. just is a pain (same with ivy bridge) cause intel decided to be cheap and not solder the IHS to the cpu. if you do a mild overclock its fine give or take how bad the tim on the cpu/ihs is. but if you plan on doing high overclocks and water cooling like this. you might as well de-lid the cpu and apply your own tim. temps on air (if done right) drop a good 15 to 20C under load. I've seen people hitting 90 C and go down to 70 or less underload. and thats on air.

    the reason why i have no upgraded from my sandy bridge 2600K. @4.5ghz right now at 1.28 volts and my max temp running intel burn test was 70C (air)
  • The Von Matrices - Monday, September 30, 2013 - link

    Please read my post in response to NeatOman. The result is correct but the reasoning is incorrect.
  • gandergray - Tuesday, October 1, 2013 - link

    For information about removing the cpu lid or integrated heat spreader, see the work performed by Idontcare: http://forums.anandtech.com/showthread.php?t=22618... .
  • iTzSnypah - Monday, September 30, 2013 - link

    You are cooling way too much with only 600mm worth of radiators and your deltaT is obscene. Take out 1x GTX780 and retest if possible.
  • NeatOman - Monday, September 30, 2013 - link

    I think the thermal paste between the cpu and the lid are the limiting factor here, i believe that not only will 4770K do better with better thermal paste in between the lid and cpu on just air cooling alone but also might have a larger difference between the air and water cooling.

    And of course there is also a full delid which i think wont be much of a threat because with water cooling you don't need the motherboard to support a large heavy cooler.
  • NeatOman - Monday, September 30, 2013 - link

    Sorry, i meant that you wont need to put a lot of pressure like if you where supporting a large air cooler with the motherboard.
  • The Von Matrices - Monday, September 30, 2013 - link

    The issue is not the composition of the thermal paste between the die and the lid; it is the thickness of the thermal paste between the die and the lid. It's widely reported that in Ivy Bridge and Haswell there is way too much of a gap between the die and the lid due to the thickness of the glue used to secure the lid to the package. You can solve this by removing the lid, using a razor blade to remove all the glue, then put on new TIM and place the lid back on the package. No matter what new TIM you use you will get drastically reduced temperatures.

    Either way, Haswell runs hot due to its FIVR, and there's nothing that can be done through beefier heatsinks, delidding, or changing thermal paste that will make it cooler than an equivalently modified Ivy Bridge.
  • dragosmp - Monday, September 30, 2013 - link

    Still, it is incomplete. The thermal transfer formula is simply Rth=rho*L/S, more thermal resistance (Rth) more the temperature delta is high between the source and ambient: deltaT=Power*Rth
    Asuming the power is constant, to decrease deltaT you need to decrease the thermal resistance, so:
    *S is the die surface, can't change that
    *L is the thickness of paste - you're right, it needs to be as thin as possible; put 2x too much and you have twice the deltaT
    *rho - thermal resistivity (1/lambda) - it depends on the material; Intel does use cheap paste with a conductivity around 3; were they to use fluxless solder or at least some AS5 they'd decrease the thermal resitance by a factor of 2 easily, thus offsetting a thicker than needed layer of paste.

    My 2 cents: for performance the paste must be removed and replaced with something better plus as you say remove the glue to reduce the thickness. Of course one should be careful not to chip the die, but these two things really help.

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