With testing under way I noticed nice and low idle temperatures, but higher ambient temperatures than was expected. With the fans at their low state in PWM the radiator runs almost passive and silent, which is no bad thing because these temps are a long way into the safe area, if things heat up further, the fans will soon kick up and take care of it.
Because of this low activity state, the H75 ran super quiet at stock clocks, with only a slight air noise being noticeable from the two fans, once installed in a chassis this is virtually silent.
Water cooling is designed (for the most part) for overclocked systems and that really reflects here, with super low idle temperatures and some of the best temps we’ve seen when overclocking, beating out the nearest rival by almost 4c. This is simply due to the push / pull fan configuration and a great example of how two fans are better than one when it comes to radiators.
Unsurprisingly the extra heat had the fans spinning a harder, but they’re still impressively quiet overall, again only a small air turbulence noise if you’ve got your ear within 2-3 feet of the unit.