Cooling Efficiency Tests
The diagram below shows the results of our cooling efficiency tests:
The first thing that catches your eye is the fact that the junior and the least expensive Nexus FLC-3000 turned out much more efficient than two higher-end models: XiR-2300 and XiR-3500. It won 12°C from the aluminum model and the whole 10°C from the copper one. Here it is, however, important to check the rotation speeds of the cooler fans, because the FLC-3000 fan is honestly PWM controlled in the entire range, while the fans of the XiR models work at 1240-1760 RPM maximum! In other words, the thermal diode installed incorrectly doesn’t really do its job right. Things didn’t get any better even after I bent the diode a little towards the bottom, so that it could be as close as possible to the hot heatsink plates: it still didn’t speed the fans up to their maximum.
However, if you look at the results of the XiR-3500 cooler with the FLC-3000 fan (the fourth results from the top on the diagram), you will notice that a faster fan helped the copper cooler improve its efficiency by 4°C compared with the results obtained with the cooler’s default fan. It means that XiR models owe their unimpressive performance compared with FLC-3000 is not only to the fans and thermal diodes, but also to a few other factors. Among them could be not the best cooler positioning (I have to remind you that we tested the XiR coolers in the only possible position: with the heatpipes ends turned towards the back of the system case, while FLC-3000 was installed with the heatpipe ends facing up). I also can’t exclude the effect of the uneven base plate: we can’t guarantee proper contact between the cooler base and the CPU heat-spreader even though the thermal compound imprints were good enough.
As for the comparison between Nexus coolers and XILENCE Black Hawk COPPER, the best top-cooler boasts an indisputable advantage over the competitors. Even in quiet mode it proved 4°C more efficient than the best Nexus offering at its maximum fan speed. And in the PWM controlled mode Black Hawk adds another 4°C to its advantage.
In addition to the previous test we also checked the maximum CPU frequency with the best Nexus cooler – FLC-3000 and compared the results against XILENCE Black Hawk COPPER at this frequency. Here is what we got:
In fact, the 3.76 GHz frequency at 1.525 V Vcore we managed to hit with Nexus FLC-3000 are a pretty good result. But XILENCE Black Hawk COPPER cools the CPU 11°C better in the same testing conditions. So, there is nothing else we can really say at this point.
Unlike the efficiency of the Nexus solutions, their acoustic performance is really remarkable. The fans work noiselessly in the interval from 900 to 1300 RPM, very quietly up to 1800 RPM and with moderate noise up to the maximum rotation speed of 2600 RPM. Like the 120 mm Nexus Basic case fans, Nexus coolers boast very low overall noise threshold that is why they will suit perfectly for HTPC systems (provided they fit in fine), because systems like that are very sensitive to noise and do not require super efficient cooling.