Not so quiet. And watch out for the fixation.
This all-in-one kit is well made and very correct for the price.
But in my case, the priority was silence, more than cooling. The problem is that the pump motor makes a permanent high-pitched noise, a kind of hissing sound.
And another problem is that you need a cut-out in the case support on which the motherboard is fixed, because the support that comes under the motherboard is very thick. In my case, the motherboard is screwed on a plate without a cutout and therefore does not allow to install it (without DIY to adapt...).