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.


Based on my data for the EK-Coolstream PE 360 tested elsewhere, I can safely say that the newer EK-Quantum Surface P360M is a significant update to where once again I am comparing this 44-mm thick radiator with the bigger, thicker boys. It fares okay at lower fan speed (lower noise) operations but really gets into its own at medium-high fan speeds. Scaling isn't as good as the higher performing thicker radiators however, including EK's own X360M which is trying hard to justify itself over the P360M here, as well as the Hardware Labs Nemesis lineup which scales beautifully across the board.


At the suggestion of some readers and industrial contacts, I added back the relative performance graph here which accounts for the liquid flow restriction and thermal performance data all together in an identical manner as what I used to before. I will still not show the performance per dollar graphs here until things stabilize in a world that has some very weird pricing for some products sold in specific markets though. The colors above are somewhat harsh admittedly but the goal here is to visually tell you where the various radiators stack in their thickness class as well as overall. The Watercool Heatkiller Rad 360-L is a 50-mm thick radiator that I decided to place in the 45-mm thickness class, and it takes the crown from the EK P360M marginally in that regard. But overall it's a good representation for all three of the new EK radiator lines, and the P360M is practically no different from the X360M here!