Unfortunately, this is where the Noctua NH-C14 disappointed. Despite being better than the NH-C12P SE14 at stock, it failed to sustain a 4GHz clock speed where its predecessor could. Generally, 4GHz is achieved by using 1.3-1.32V on my i7 920 chip but this proved too much for the cooler. Temperatures rose to 100C fairly quickly, and the CPU started throttling to lower clock speeds. My own assumption is that the size of the heatsink doesn’t provide a large enough surface area to dissipate the heat generated and it quickly becomes saturated. At stock clocks, the airflow dominates cooling, hence the advantage of the two fans compared to the NH-C12P. At 4GHz, the heatsink itself becomes the limiting factor. It is understandable that such a cooler can’t cope with such a high overclock, given its purpose as a low profile top down cooler but it is disappointing that it couldn’t match up to the older NH-C12P SE14.
However, all overclocking hope is not lost. The test prompted me to look at the maximum clock speed it could sustain on my i7.
At 3.9GHz, the NH-C14 still managed to cool the i7 without it throttling or reaching absolute temperatures in the upper 90s. 4GHz required a voltage hike that increased the heat generated above acceptable values (100C).
**Update**
Following a few conversations with Noctua and being somewhat unimpressed with the overclocked performance ,I tried to investigate what could be limited the cooler. As I have mentioned, Noctua recommend that the cooler be orientated with either the heat pipes being horizontal or the C bend facing downwards. Since the CPU socket on the Rampage III extreme is placed unusually high, it was impossible to test the cooler such that the heat pipe ends faced the top of the case and the C bend faced downwards so I had to settle with the heat pipes facing to the sides. Ideally, we want the former configuration so that the vapour in the heat pipes can travel upwards and then condense into a liquid and subsequently flow downwards. In the end I decided to lay my case flat rather the upright so that the orientation of the cooler didn’t matter for optimal cooling. So here are the results:
Unlike before, the Noctua NH-C14 manages to handle the 4GHz clock speed and more importantly, it does so with Noctua levels of expectations. I was personally amazed that simply changing the orientation of the cooler could have such a large impact despite Noctua stating that the previous method I used was acceptable. Although I couldn’t have it facing vertically upwards, having the case and cooler lying flat rather than upright simulated these results. Immediately, we see that the default Noctua configuration managed to outperform the original NH-U12P significantly and beats the likes of the Corsair H50, CoolIT ECO A.L.C, Corator DS and the Nordwand. We also have to remember that the Noctua is the quietest solution of the lot. It was a mere 0.25C behind the mighty Prolimatech Megahalem, demonstrating Noctua’s amazing engineering.
In its other configurations, having the fans reversed resulted in worse performance and the same goes for using the U.L.N.A. Coincidentally, those two configurations yielded the same results. For those looking for a low profile cooler, the respective setup still achieved very impressive results that match the NH-U12P. Users no longer have to compromise on cooling in their quiet HTPC or LAN rigs.
