System noise
Five of our coolers have been tested for noise, and the results serve up some good news as well as some bad.
With our test system idle and the Hydro H80 and Hydro H100 configured to run in Quiet mode, system noise is kept down to a bare minimum. In this scenario, both coolers are barely audible - though, not quite as quiet as the single-fan Hydro H60.
Crank up the load and switch over to Performance mode, and things take a turn for the worse. After 30 minutes of Prime95, we recorded system noise at 54.6 dB for the Hydro H80 and 55.1 dB for the Hydro H100. That's uncomfortably loud, and to put the numbers into perspective, the Intel DBX-B cooler is very loud at 48.2 dB, and the Antec Kuhler 920 is intolerably loud at 60.8 dB.
And there's another concern, too. At the start of our benchmarks, we found our Hydro H80 pump to be unusually loud - giving off a grinding noise akin to that of a mechanical hard drive. The issue appeared to be trapped air inside the unit, and we were able to solve the problem by gently rotating our radiator to dislodge the air. A quick look on Corsair's support form suggests that we aren't the only users to experience trapped air, and this potential issue highlights one of the pitfalls of a closed-loop system; there's no option to bleed the unit, so if you are suffering from a noisy pump/trapped air, your only option may be an RMA.
