Our overclocked test is the main stress test and represents a very tough challenge for these CPU coolers. As we are locking the voltage and clock speed, the temperature figures are directly comparable between competing coolers.
We see package powers in the order of 220W for the CPU and wall power levels that exceed 300W for the system. There is a caveat whereby lesser performing coolers force the CPU to run at higher temperature levels. This, in turn, reduces the operating efficiency and dictates that the CPU draws more power. This increased power draw results in higher operating temperatures, thus further negatively affecting the thermal performance.
This small degree of thermal runaway – albeit very limited in system divergence terms – is important with our manually overclocked 5950X CPU. It perhaps seems unfairly weighted against the lesser performing CPU coolers. But it is the reality of real-world operation whereby higher performing CPU coolers can sometimes show disproportionately better temperature performance at the higher thermal load levels.
Note the use of delta temperature data in our charts and factor in your own ambient conditions for reference.
Based on full fan and pump speed performance, the Fractal Lumen S36 RGB is an excellent choice for our heavily overclocked Ryzen 9 5950X test processor.
Fractal's new 360mm RGB model is able to outperform all other comparison products in our chart, except for the high-end (and expensive) Asetek-based Phanteks 360mm AIO. And the margin of difference there is very small.
Factoring in price and noise output at this early stage, the Fractal cooler looks incredibly promising.