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.