Thankfully, good practice also happened to be the easiest thing to do. Before powering on the system, you need to fill the pump and reservoir with coolant and get the coolant circulating while checking for leaks. I actually happened to have a separate 4-pin molex power supply handy from a USB hard drive kit, so I was able to power the pump without needing to even touch the AX1200i. You really don't want to run the pump without coolant in it any longer than you have to, but you'll want a decent amount of coolant in the reservoir to start (have a towel handy in case you accidentally overfill like I did) and then slowly add coolant until it's clear you don't need any more. For me, I had a pretty good idea I didn't need any more when the whole thing overflowed again. But at least I didn't have any leaks.

Leave the pump running for a few minutes, and rock the case back and forth to work air bubbles out of the system. Take a flashlight and look at each of your interconnects and make sure none of them are leaking. For the record, I wound up going through about one and two-thirds bottles of the HydrX.

After getting coolant circulating through the system and all of the air out (you'll know the air has been released when the coolant level in the reservoir has a sudden drop and there are no leaks), I went back to threading all of the power cables and very carefully cramming everything into that hopelessly small space.

The last problem I ran into had to do with Swiftech's PWM splitter. While it's supposed to take the PWM signal from the motherboard and split it among all of the fans connected to it, the fans all wound up just running at full speed. It's tough to figure out exactly where the blame lies or if it's just an incompatibility. Honestly, I think a rig like this is pretty much the ideal situation for a Corsair Link kit, where extremely tight and flexible software control of multiple PWM channels is vital. Gigabyte has made a fantastic motherboard here in the G1.Sniper 5, but their fan control is still woefully lackluster.

Apart from my fan control woes, though, I found that I was ready to close the shiny new system up and get to testing.

Putting It All Together, Part 3 Overclocking Under Water
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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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