Benchmarks: Temperature and Noise
Noctua's NH-U9DX i4 has no problem dealing with the 4GHz CPU overclock - 64ºC under maximum load is nice and cool for a 140W chip. The graphics card, on the other hand, is a little closer to the limit and throttles back a notch in order to keep below 80ºC. During our benchmarks, the GPU began by boosting to 1,437MHz but would occasionally dial down to 1,392MHz in order to keep to the target temperature.
Performance has been impressive throughout, and there's good news on the noise front, too. Our sound meter recorded a quiet idle noise reading of 33.6dB, and note that the GPU fans switch off at this point so all you're hearing are the case fans, the Noctua cooler and the PSU. That figure rises to 37.4dB when video encoding and 40.7dB when gaming, with the CPU and GPU fans ramping-up accordingly. The latter two are clearly audible, but considering the size of the box and the calibre of hardware, some amount of noise is to be expected and the Nanu Carbon is far from offensive.
What's interesting is that Scan has erred on the side of caution by choosing 'standard' fan profiles in the BIOS. Because we like our PCs to be deadly quiet, we manually switched the CPU and chassis fans to 'silent' and saw idle noise drop to 28.8dB - that's practically inaudible and low enough for the Nanu Carbon to be considered as a high-performance HTPC solution.
One other point of interest is coil whine. How much you get tends to differ from one GPU to another, but we did find it noticeable on the overclocked GTX 980 Ti in certain titles, so that's something to bear in mind if you pick up on every little noise.
