And it only added 100$ to the cost of a normal gtx980 card at 650$.
It's $100 for AIO CLC, and overclocking to 1393mhz - all warrantied.
That's a bargain and why cards like EVGA Classified 980 have been dropping to
$575 because it's better to get the 980 Hybrid over a $699 EVGA Classified. (that and because 980Ti and 390X are coming)
db meaurements can be somewhat misleading since the human ear is A-weighted and certain frequencies are perceived to be louder than others, sometimes many times so. Also the other issue is water pumps do have mechanical vibration which can cause a case to resonate, so measuring the noise at the fan is not the same as the sound several feet away where case resonance can cause an echo effect. My personal experience was the EVGA 980 AIO sounded significantly louder than the stock Titan X fan at idle.
But one can combat higher idle noise levels by setting up a custom fan curve or replacing the included fan with the AIO CLC. To lower the overall noise of a system, since you no longer require a well-ventilated case (because the AIO exhausts most of the heat out of the case), you can buy something like a Fractal Design R4/5, etc. and line it up with sound dampening material. How am I going to lower the noise levels of a card that runs at 56 dBA at 86C?
Now what about 2 of those in CF/SLI? As a gamer, you are screwed. Your ONLY options are (1) get a high end after-market open air cooler like MSI Lightning or Vapor X, but this is problematic for Tri-GPU or even dual-GPU setup in some cases; (2) go water blocks - most expensive option; (3) buy your own AIO CLC - but then you have nothing warrantied.
JaysTwoCents tested Hybrid 980 and it also overclocked to 1.6Ghz while remaining whisper quiet and temps never exceeding 53*C:
https://www.youtube.com/watch?v=98P_NjK3ft8
Now imagine an AIO CLC on a 275-300W GPU where you are overclocking it, adding another 100W of power. Most GPU air coolers would be struggling. With AIO CLC, the heat from the GPU is exhausted out of the case too.
Also, if you want a minITX or a PCB 30-50% smaller than a Titan X, water-cooling is going to be a requirement.