Thermal Performance

For CPU water block thermal performance, I use my Core i7-5960X on the ASUS Rampage V Extreme motherboard with the CPU overclocked to 4.4 GHz at 1.3 Vcore and paired with 4x4 GB Corsair Dominator Platinum DDR4 RAM at 2666 MHz (CAS16-16-16-18). A Swiftech MCP35x2 pump, an Aquaero 6 XT controller, and a Black Ice Nemesis GTX 480 radiator with Noiseblocker NB-eLoop B12-3 fans complete the loop. The GPU is not placed in the loop to make the only source of heat the CPU and, thus, the CPU block itself. Average flow rate is set to 1 GPM and calibrated in-line temperature sensors are used to measure the coolant's temperature.

Everything required is placed inside a hotbox, and the ambient temperature is set to 25 °C. Gelid GC-Extreme is used as the thermal paste of choice and cure time is taken into consideration. Three separate mounts/runs are done for statistical accuracy and to remove the chance of any mounting-related anomalies. For each run, a 90 minute Intel XTU stability test is performed. XTU is a stability test from HWBot that uses a custom preset of Prime 95 (no AVR), which ensures the load is uniform on each run. CPU core temperatures are measured using Aida64, and the average core temperature is recorded at the end of each run. A delta T of CPU core and loop temperature is thus calculated for each run, with an average delta T that is then obtained across all three runs. This way, the cooling solution is taken out of the picture. The effect of block orientation is also tested, and the best orientation is used for these runs, with the result shown below.


Note that newer blocks are not necessarily designed with the now-older Intel X99 platform in mind, which in turn also had a more concave-to-flat IHS instead of the convex-to-flat IHS we see in more CPUs today. I am working on updating my test system, but as it stands, the EK-Velocity CPU blocks tested do not appear near the top of the leaderboards here. If anything, both fared worse than the older EK-Supremacy EVO with the nickel/plexi option, although the EK-Velocity RGB nickel/plexi was essentially the same when rounded off. The copper/plexi version is within error margins, as is the case with a lot of CPU blocks today. Physics is a great limiter, but I am still left wondering if EKWB did the right thing with their cooling engine update here. Perhaps with everything accounted for, we will be able to tell a better story and thus, we move on to the next page for that.