First: Last Gen NZXT X61 vs. New X62
Before getting to the competitive analysis between multiple brands, we wanted to start with a generational head-to-head between NZXT's previous X61 and current X62 product offerings. The X61 is still priced for ~$115 on Newegg and is still available, with the X62 coming soon (at time of writing) and with an MSRP of $160.
The X62 uses a Gen5 Asetek pump and new NZXT fans, which have a maximum RPM of ~1700RPM. The X61 model's fans operate at a maximum of ~2000~2100RPM, but seem to move less air rotation-for-rotation. We'll look at that here. The biggest at-a-glance difference, obviously, is the more limited LED offering on the X61 cooler, which just illuminates the NZXT logo with a solid color.
Here's a look at the simplified thermal chart:
The thermal difference alone, RPM-to-RPM, is actually somewhat substantial. NZXT has managed to reduce temperatures at a relatively silent RPM of 1050 by roughly 5C, from 42C to 37C load. The high-end performance isn't as distant, with the X62 at 1700RPM operating at 34.63C load, while the X61 is at 36.94C load. Note though that the X61 can run its fans at 2000RPM if desired, where the X62 caps at 1700RPM.
Here's a look at the noise results on a scatter plot. The Y-axis represents temperature in degrees C (dT over ambient). The X-axis represents noise (dB) after accounting for the noise floor (~25~26dB). Note that, as we talk about these devices, we are talking about total system noise. We're using a passive PSU and the cooler is the DUT, with no case fans attached, so it's mostly the cooler and pump noise output -- but there's still a GPU blower fan at 23% RPM from the 980 Ti GPU. Not a big deal, but worth noting as it does contribute to the system noise floor.
The X61 at 1050RPM is approximately equal in noise output to the X62 at 1050RPM, with the newer cooler performing imperceptibly louder. The 5C temperature reduction for a 0.3dB noise increase is well worth the trade, and can most likely be attributed to the Gen5 Asetek pump and to the new fans that NZXT is using. At 1700RPM, noise levels for the X61 are around 51.4dB, where the X62 is one-tenth a decibel higher at 51.5dB, but with a 2C reduction in temperature. This X61 unit is a few years old, but we've not used it aside from the initial benchmarks. The only possible reason there would be performance degradation from off-the-shelf performance would be if permeation had become an issue in that time, which shouldn't be the case; these coolers are minimally rated for about 5 years of use.
That's a good start for the new coolers, but we need to compare them outside of a vacuum.
Corsair H100iV2 vs. NZXT Kraken X52
This chart looks at a few more devices. We've introduced the Corsair H100iV2 at 3x RPMS -- 2500RPM, its max, 1500RPM, and 1050RPM. We've also introduced the NZXT Kraken X52 at 2100RPM -- its max -- and 1500RPM, with two low RPM outputs of 800 and 400. We have removed the X61 for ease of viewing.
The Corsair H100iV2 is a 240mm radiator priced at $105, making it the direct and cheaper competitor to the X52 240mm radiator. NZXT and Corsair use the same generation pump, but NZXT's is heavily customized -- including PCB customizations that will allow NZXT to patch firmware in the future -- despite similar thermal performance. Corsair's pump is basically a stock Asetek unit, with some Corsair badging and SP120 fans that Corsair designed in-house.
The X62 naturally tops the charts -- it's a bigger surface area radiator and has larger fans -- but Corsair's H100iV2 sits just ahead of the Kraken X52 when comparing max RPMs. That's the nature of a higher RPM on Corsair's fans. We'll get to noise in a moment. The difference between the devices at their max RPM is approximately 1C -- not noticeable, really, and bearing no impact on CPU performance. RPM for RPM, with both devices at 1500RPM, we see that the X52 is superior to the H100iV2 by approximately 1C -- also not really that significant, but definitely measurable.
As for the X52 with its lowest, quietest fan speed settings, 400RPM is completely pointless. Don't set your fans this low. NZXT should not detect a PWM signal this low on their fans, as they become completely useless and don't push any air at all. If we stop using delta values for a moment and add ambient back in, we reveal that the CPU temperature is nearly 95C. Why NZXT allows the PWM signal to detect and output a fan speed that is so dangerously low is beyond us, but it should be capped at closer to 800RPM. Even there, we're still getting a 75-77C output -- or 55.61C delta T -- though the noise levels are at 30.2dB and unbeaten with our current line-up.
Let's add dB to get a better understanding of which device truly is superior.
With dB accounted for, we now see that the Corsair H100iV2 at 1500RPM is operating with a decibel level of 41.8dB, where the NZXT Kraken X52 at 1500RPM runs 42dB -- so a difference of 0.2dB. Again, not really significant or observable to the human ear. If all that matters to you is cooling and noise, and the LEDs and aesthetics are valueless, then the H100iV2 ($105) is clearly a much cheaper option for those two metrics. But there's a better mix still, if we ignore price temporarily.
We're seeing the X62 at 1050RPM operating with a lower temperature than any of these devices, excluding only the H100iV2 at 2500RPM -- or a borderline intolerable noise output of 53.9dB. The X62 at 1050RPM outputs at 37.4dB, with a load temperature of 37C, versus the H100iV2 and X52 devices both at around 42dB and 40C for their 1500RPM performance.
Time to add more devices to the charts. We're staggering them to keep it legible.
Kraken X62 vs. EK Predator 280 XLC
Here's a look at performance with the next competitor added: The EK Predator 280 XLC. Note that this $210 cooler is meant for creating semi-open loop cooling, as it uses quick release valves to couple with pre-filled waterblocks for GPU cooling. In this scenario, we're only testing the Predator's CPU cooling ability, and have not hooked a GPU into the loop. EK is using a copper radiator that's fatter than its competition, alongside two custom 140mm fans. The Predator maxes out at 1400RPM, but has a much lower bottom line of 600RPM while still remaining under operable temperatures.
The Predator also has the third-best temperatures on the bench, only marginally behind the X62 from NZXT -- though not exactly linearly comparable given its significantly higher price and more customizable loop formation. Still, at 35.92C, the Predator 280 is off to a good start.
The Predator 280 is still able to impressively operate at 49.3C with a 600RPM fan speed, which, if we move now to the noise chart, outputs at 29.2dB. The Predator at 600RPM is the quietest on the bench while remaining capable of cooling the CPU reasonably. Its 1400RPM performance lands it at 41.4dB, or about the same volume as the Corsair H100iV2 at 1500RPM but with 5C cooler performance. It's also about 0.4dB louder than the X62 at 1050RPM, which is effectively equal in cooling performance.
NZXT Kraken Liquid Coolers vs. Air Coolers
And finally, let's add all the devices to the charts. This new thermal chart adds the Be Quiet! Dark Rock 3 at 2000RPM for a look at a $50 air cooler's performance, but also adds the X42 140mm Kraken series cooler.
The X42 is able to keep up with the 240mm coolers only when maxing its RPM, which lands the 140mm device at 40.6C. The X52 is about 1C cooler with a 200RPM reduction to fan speed -- but runs two fans and a larger radiator. The X42 at 1050RPM operates at 46.2C, really damn close to the H100iV2 at 1050RPM, though the price is unfortunately still higher than Corsair's cooler. If the X42 were priced below or around $100, it'd make a whole lot more sense as a product, based on these results. The thing is 9C cooler than the Dark Rock 3 air cooler, which costs $50 these days.
This noise chart has undergone some culling. We're looking at the nearest competitors -- so the H100iV2, the Kraken coolers at just a few of the most relevant RPMs, and the Dark Rock 3.
The Be Quiet cooler sits at 55.09C load with a 37.7dB at 2000RPM, while the Kraken X42 at even just 1050RPM sustains a 35dB and 46.2C output. Still, the X42 is readily beaten in noise and temperature by the H100iV2 and other Kraken products.