Earlier this year, Corsair announced its Hydro Pro series of closed-loop liquid coolers. Those heatsinks introduced a stylish new pump-head design kitted out with RGB LED lighting, and they tapped Corsair’s exceptional ML-series fans for air-moving power at the radiator end. The first two heatsinks in that series covered two important bases: the H115i Pro for 280-mm radiator mounts, and the behemoth H150i Pro for cases with 360-mm radiator hardpoints.
The bread and butter of the closed-loop liquid-cooler market lies in smaller radiators, though, and 240-mm heat exchangers are the place to be for most builders with mid-towers and mainstream CPU sockets. Today, Corsair is rounding third and headed for home with the 240-mm H100i Pro.
Since the radiator size on this cooler is the only thing about it that’s changed versus its larger cousins, we won’t recap every detail of this new series of heatsinks here. If you want that in-depth look, have a gander at our review of the H115i Pro and H150i Pro now. Instead, we’re going to concern ourselves with noise levels and cooling performance first and foremost.
There is one major change on the H100i Pro apart from its radiator size. The H100i’s pair of Corsair ML120 fans can spin all the way up to 2400 RPM, compared to 1600 RPM from the ones included with the 360-mm heatsink. Both coolers have a 400-RPM minimum fan speed. You can’t tell the low-speed and high-speed fans apart externally, though.
Past that, the H100i maintains the same simple mounting system, integrated fan controller, RGB LED illumination, and most everything else we liked about the first two Hydro Pro-series coolers. Let’s see how it performs.
Our testing methods
Here are the specifications of our test system:
|Processor||Intel Core i7-6950X|
|Motherboard||Gigabyte X99 Designare EX|
|Memory||32 GB (4x 8 GB) Crucial Ballistix Elite DDR4-2666|
|Graphics card||Gigabyte GeForce GTX 1050 G1 Gaming|
|Storage||Intel 750 Series 400 GB|
|Power supply||Seasonic Prime Platinum 1000 W|
|OS||Windows 10 Pro|
Our thanks to Gigabyte, Intel, and Corsair for helping us to outfit our test systems with some of the finest hardware available. Aerocool provided the P7-L240 that will serve as the foil to the H100i Pro today, as well.
To test heatsink performance, we run the Blender “classroom” benchmark file three times in succession and report the maximum CPU package temperature observed in HWiNFO64. Blender is a demanding real-world workload that can still stress an overclock to failure. Prime95 Small FFTs generates a lot of heat, sure, but the heat and power consumption it generates are both far in excess of any real-world application we’ve ever observed.
Although our recent heatsink reviews have used Intel’s massive Core i9-7980XE as a heat source, the fact that the latest Extreme Edition chip uses thermal interface material rather than solder under its heat spreader has bugged me while testing CPU coolers. We want our performance results to be limited as much as possible by the performance of the cooler under test, not the thermal transfer capability of a variable we can’t control.
With that in mind, I set aside our X299 test rig in favor of the Core i7-6950X and its soldered heat spreader. At 4.4 GHz and 1.38 V, the ten Broadwell cores of the i7-6950X are still a formidable match for any cooler. We’ll see whether the move to solder helps tease out any performance differences from these heatsinks.
The ambient temperature of our testing environment was maintained at 78° F, plus or minus roughly 1° F, over the course of each test by monitoring with a calibrated thermometer throughout.
Overclocked cooling performance
No revelations here, really. The H100i Pro beats out the already-impressive Aerocool P7-L240 by 2° C under these conditions, and that’s good news for the Corsair heatsink. Still, the margin of victory is slim. Let’s see if our noise measurements can put some distance between these coolers.
To measure noise levels, we use the Faber Acoustical SoundMeter application running on an iPhone 6S Plus. Measurements were taken 18″ from the intake side of the radiator on our test bench.
Turns out that the H100i’s performance comes at a price. At idle and at the 1000 RPM speed we’ve picked to represent light spikes in usage, both of these coolers are practically neck and neck if you go by our meter. To deliver its cooling-performance victory above, however, the H100i Pro has to get noticeably louder at full speed.
dBA measurements don’t tell the whole story, of course. At 1000 RPM, Corsair’s fans barely make any noticeable sound at all. At full speed, the Corsair spinners have a mild but noticeable high-pitched tone. Even so, their overall noise character is remarkably broad-spectrum and pleasant, although it’ll likely be difficult to ignore entirely thanks to its high volume. Still, I was shocked to see that 54.3 dBA number on my meter. The ML120s sound like much quieter fans to the ear.
Past Corsair 120-mm fans really let it all hang out when operating at their limits, so the refinement of these high-speed ML120s is welcome. Even though the Aerocool P7-L240’s fans are quieter in absolute terms, their noise character is considerably more complex than that of the Corsair spinners.
The one potential shortfall in the H100i Pro’s noise character comes from its pump head. Like its 280-mm and 360-mm siblings, the pump on the H100i Pro isn’t the smoothest-sounding affair. The pump’s quiet mode lets it fade into the background of our otherwise library-like testing environment, but its balanced and extreme modes reveal a gravelly whine that’s harder to ignore. I normally would be willing to forgive this behavior, but the Aerocool P7-L240’s pump is nearly silent even at full speed and has no such rough edges.
If the H100i Pro could dynamically adjust pump speed in response to coolant temperatures, I would be willing to forgive it this annoyance, but it can’t—switching pump speeds has to be done manually through iCUE every time a builder anticipates a change in load conditions. Changing the cooler’s pump speeds from even the balanced mode to the quiet mode has a major impact on performance, too, so builders can’t just set up quiet mode and forget it on demanding systems.
Corsair markets the H100i as a quiet cooler, and it can certainly be that if its owner wants. That tack sells the performance of this heatsink short, though. Though its margin of victory wasn’t a large one, the H100i proved more capable at cooling our test system than even Aerocool’s P7-L240, a recent 240-mm favorite of ours.
That high performance does come at a cost. The H100i gets quite a bit louder than the P7-L240 under full load, even if the excellent noise character of its bundled ML120 fans blunts the edge of the absolute sound pressure levels at play. The sound quality of the H100i Pro’s pump at full tilt is also a bit intrusive when the rest of a system is idling, and the mass of bundled cables from the H100i’s pump head might annoy some builders, too.
Of course, it’s not necessary to run the H100i Pro all-out all the time. At moderate pump and fan speeds, Corsair’s latest can barely be heard at all, and those settings are plenty capable of keeping stock-clocked CPUs in check. The aluminum-and-RGB-LED-accented pump head on this cooler looks as good as ever, and its mounting system is easy to use and easy to adapt to different CPU sockets.
All told, the H100i has range. It can be as quiet or as powerful as a builder needs it to be, it’s easy to install, and it’s competitively priced for the performance it delivers at $120 list. If the iCUE utility ever learns how to switch pump speeds in response to coolant temperatures, Corsair’s Hydro Pro-series coolers will be nigh unstoppable. For the moment, the H100i comes TR Recommended.