NZXT Kraken X31 Liquid CPU Cooler Review

Testing
The test rig consists of the following parts:

Processor: Intel Core i7 3770K
Motherboard: Gigabyte G1.Sniper3
Video Card: EVGA GTX 690
Memory: Samsung Green MV-3V4G3D/US – 16GB
Power Supply: Enermax Maxrevo 1350W
Storage: OCZ Vertex 3 240 GB raid 0 Running Windows 7 64bit
Cooling: NZXT Kraken X31
Case: Phanteks Enthoo Luxe

As always testing was done using Intel Burn Test (IBT) with the AVX instruction set. The reason to use this instead of Prime95 with this setup is that it pushes our i7 3770K a whole lot harder. This gives us a better sense of extreme load temps. Most of the testing was done at the max memory setting for a single pass. While admittedly this in no way would qualify the chip as stable while overclocked, it gives us a realistic idea of what temps it will be hitting. Additionally we are going to run 3DMARK Fire Strike Extreme to give you a realistic idea of performance while gaming.

Our baseline was established using a bequiet! Dark Rock Pro 2 with the 3770K on stock settings:

Ambient temps: 22.22°C/72°F
Idle temps: 38.75°C/101.75°F core average
IBT temps One Pass Max Memory: 63.5°C/146.3°F core average

Since the Kraken X31 is designed to be used with the CAM software we used it for all of our testing. It is a very well designed suite packed with real time graphs and plenty of software controls. You can adjust the fan speed manually, set up a custom profile, or choose one of the preset profiles . I especially like the CPU core temperature reporting which automatically averages your core temps for you. This is great when you just want to take a quick look at your overall temp. However if you still love having all the individual data, clicking “Advanced Mode” under the SPECS heading while on the BASIC screen will provide all the grainy details of your rig in real time. In addition to all this, NZXT has the mobile app that allows you to access CAM without having your mouse in hand. For our purposes I set our profile to “performance” but still used Hardware monitor to gather our temperature data and got down to testing.

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The first thing I checked out was our fan speed. I set the Kraken to manual and cranked it to 100% fan and let it ride for a few minutes. As you can see ~ 1920 is the max rpm we achieved. So close, but just a little shy of the 2000 rpm claimed max speed.

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Now let’s get to the real stuff and see how the X31 performs. Here are the results using stock settings and the Kraken X31:

Ambient temps: 17.78°C/64°F
Idle temps: 33.25°C/91.85°F core average
IBT temps, One Pass Max Memory: 59.25°C/138.65°F core average

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After we adjust for our 8°F ambient temperature difference (thank you winter) we find that the X31 is 1.9° F cooler during idle. Unfortunately during our run of IBT we found that the X31 was actually .35°F warmer than our baseline. Now remember we aren’t comparing with the Intel stock cooler here, this is a very decent air cooler. What this means is we are simply below baseline on stock settings during IBT. One thing I do like in the results is a very tight grouping of core temperatures which means we have a good even contact with the CPU heat spreader.

For the next test we overclocked the CPU to 4.5ghz instead of simply going for a max overclock and are simply going to shoot to hit 4.5ghz pass or fail. If the cooler will allow our 3770K to hit 4.5 ghz we note the temperatures and move on to test it on 3DMARK Firestrike Extreme. If not then back down to a more acceptable and stable overclock. Not as extreme, but slightly more consistent and far more analogous to normal use.

Here are our results for our i7 3770K @ 4.5ghz with 1.248V vCore:

Ambient temps: 17.78°C/64°F
IBT temps: 78.75°C/173.75°F with one core hitting 83°C

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Although we aren’t setting records with the X31 (and we shouldn’t have expected to) we did hit 4.5ghz and pass with acceptable temperatures. This means we are safe to proceed with some game like testing and for us that means 3DMARK’s Fire Strike Extreme at 4.5ghz:

Ambient temps: 17.78°C/64°F
3DMARK: 65.25°C/149.45°F with two cores hitting 68°C

I can see how you might be disappointed with these results, but I don’t see it that way. Sure the X31 isn’t top dog when it comes to performance. But really it was never going to be. It is after all NZXT’s first tier AIO cooler. One thing I have to say that I am super impressed with is the sound levels. Even in performance mode you really don’t notice the fan running on this cooler. It’s one of the first AIO’s we’ve tested in a long time that simply blends in and doesn’t make itself known even when it’s working hard. The pump parallels this theme, by that I mean you never hear it. The most noise this unit ever made was some gurgling when it started which went away when the air bubbles cleared.