Thermal Performance

Given the installation issues with my LGA 115x test rig, I used my i7 5960x on the Asus Rampage V Extreme motherboard instead. The CPU was 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 completed the loop. The GPU was not placed in the loop so that the only source of heat was the CPU and, thus, the CPU block itself. Average flow rate was set to 1 GPM and calibrated in-line temperature sensors were used to measure coolant temperature.

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


When there is just over 3 °C of difference between all the blocks tested so far, you know things are hard to distinguish. The Bitspower Summit EF-X falls in the lower half of the table here, but only just and not by much. Disappointing here, though, is the measly 0.2 °C improvement from the predecessor Summit EF. Overall, there is not much to say here - thermodynamics is a huge equalizer. If you are looking for flagship-level performance and want every single tenth of a °C, however, there are better options available.