Please note that our "under load" tests aren't conducted in an absolute peak scenario. Instead, we have the cards running a real game, Crysis 3, in order to show us power draw with a more typical workload.
In the Fury X, AMD has managed to deliver a substantial upgrade in GPU performance over the R9 290X with lower power draw while gaming. That's impressive, especially since the two GPUs are made on the same 28-nm process technology. The Fury X still requires about 50W more power than the GTX 980 Ti, but since its liquid cooler expels heat directly out of the PC case, I'm not especially hung up on that fact. GCN-based GPUs still aren't as power-efficient as Nvidia's Maxwell chips, but AMD has just made a big stride in the right direction.
Noise levels and GPU temperatures
These video card coolers are so good, they're causing us testing problems. You see, the noise floor in Damage Labs is about 35-36 dBA. It varies depending on things I can't quite pinpoint, but one notable contributor is the noise produced by the lone cooling fan always spinning on our test rig, the 120-mm fan on the CPU cooler. Anyhow, what you need to know is that any of the noise results that range below 36 dBA are running into the limits of what we can test accurately. Don't make too much of differences below that level.
The Fury X's liquid cooler lives up to its billing with a performance that's unquestionably superior to anything else we tested. You will have to find room for the radiator in your case, though. In return, you will get incredibly effective cooling at whisper-quiet noise levels.