Cooling Efficiency Tests
The results of our cooling efficiency tests performed at 4.2 GHz CPU frequency and 1.35 V Vcore are summed up in the diagram and table below:
In fact the results are pretty predictable. Despite its new composite heatpipes, the not very large Zalman CNPS7X LED has barely coped with the CPU at the minimal speed of its 92 mm fan. Although at 1530 RPM the processor temperature drops by 8°C and at maximum speed of 1950 RPM – by 14°C. In this mode Zalman CNPS7X LED can compete against Thermalright True Spirit with its fan rotating at 800 RPM. I am sure you understand that it doesn’t make any sense to compare the cooling efficiency of these two products with the level of noise being so dramatically different. As for Thermalright True Spirit, the efficiency of its relatively thin heatsink proved to be dependent on the fan rotation speed.
You probably wonder where the comparison against Zalman CNPS10X Performa is. It is coming. We had it done at 4.3 GHz CPU speed and 1.39375 V Vcore. The results of this comparison are in the following table and diagram. We also added results of Thermalright Archon with one default Thermalright TY-140 fan for reference purposes:
Zalman CNPS7X LED has barely coped with a six-core processor at average fan rotation speed. It proved about 4°C more efficient at maximum fan speed. Unfortunately, this was the best overclocking we could do with this compact cooler.
The slightly less expensive Thermalright True Spirit cooler does much better here. Not only was it capable of keeping the overclocked CPU stable at 800 RPM fan speed, but also outperformed a powerful Zalman CNPS10X Performa cooler. And it was superior in the entire fan rotation speed range. True Spirit sported a 4-5°C advantage in quiet modes and was about 1-3°C ahead in noisy modes, but it was stably ahead in all of them. Of course, we couldn’t help checking out how far it would be possible to overclock our test processor using Thermalright True Spirit cooler at 1730 RPM fan speed. It turned out that this light-weight and inexpensive product can cool our 6-core processor properly at 4.4 GHz clock frequency and 1.44375 V Vcore:
In this case the peak temperature of the hottest processor core reached 92°C. Thermalright True Spirit was also additionally tested with two Thermalright TR-FDB fans installed for air intake/exhaust. It turned out that replacing the single default fan with two alternative ones working at the same exact speed allowed lowering the maximum processor temperature by only 2-3°C. In fact it is quite logical, because you can hardly expect a second fan to do much good to a thin heatsink like the one of the True Spirit cooler.