Thermal Performance

Everything needed—monitor, peripherals, motherboard w/CPU and GPU, radiator, PSU, and so forth—is placed in a sealed, climate-controlled box at 25°C +/- 0.05 °C. Each radiator is connected by Koolance QD3 quick disconnects for easily changing the fans and radiator. The flow rate is held at 1 GPM constant flow rate. The CPU, an Intel Core i7-4770K at 4.6 GHz and 1.3 V, is held at a constant load using a custom Intel XTU profile, and the GPU, an EVGA GTX 780 Ti Classified under load from Unigine Heaven 4.0 at 1080p with extreme HD settings, is overclocked and overvolted in such a way that the total system power draw is 550 W as measured by an external power meter. It's older hardware now used simply for a consistent source of heat into the loop rather than getting discarded as e-waste!

A near-constant heat load into the liquid loop by the addition of the CPU and GPU helps quickly achieve stable liquid-loop temperatures as measured by three separate in-line temperature sensors hooked up to an Aquacomputer Aquaero 6 XT. The tubing and fittings are insulated by a sleeve heater, but its heat function is not utilized. Every single measurement is done twice as a means of verification. Any possibility of running a fan outside of its static maximum RPM is minimized as much as possible by using a comprehensive series of separate fans (Noiseblocker eLoop, B12-1 through B12-4) to cover a broad RPM range while minimizing fan speed variance and, thus, airflow. The results below are the ∆T (coolant temperature - ambient temperature) in degrees Celsius.


Hmm, maybe it was the impressive NexXos HPE-45 I just tested prior to this, but I had higher expectations. As it stands, the Alphacool NexXxos HPE-30 is barely any better than the thinner, older, less expensive NexXxos ST25 most of the way. It does well compared to the thinner radiators here, but it's still closer to the typical 30 mm class radiators than the unicorn that is the Black Ice Nemesis GTS at lower fan speeds, before the louvered fins and higher fin density eventually help at medium-high airflow regimes. Scaling is thus average, but doesn't last long owing to the physical limitations of the thinner form factor.