Cooling Efficiency and Acoustic Performance

During Linpack tests inside a closed system case using the “weakest” cooling system of the today’s testing participants  we managed to overclock our 45 nm quad-core processor to 3.68 GHz (+22.7%). The nominal processor Vcore was increased to ~1.475 V in the mainboard BIOS (+28.3%):

During the OCCT tests in the same conditions the CPU remained stable up to 3.83 GHz (+27.7%) at 1.525V (+32.6%) Vcore.

The cooling efficiency readings are shown in the table and on the diagram below (the coolers are grouped according to the testing conditions – case or open testbed):

Click to enlarge

The results of our today’s test session show that Thermaltake SpinQ cooler is the least efficient of all three. Of course, it does ensure stable operation of a quad-core processor moderately overclocked to 3.68 GHz in Linpack and more aggressively overclocked to 3.83 GHz in OCCT. However, it is defeated by the other two testing participants. As its turbine speeds up, the cooler efficiency improves by 5°C in Linpack and 2~4°C in OCCT. I can’t say that Thermaltake SpinQ efficiency depends greatly on the type of testbed (open or closed case), because the results obtained on both testbeds are just a little different.

The second hero of our today’s test session, ASUS Royal Knight, turned out a better balanced and more efficient product. The CPU temperature in Linpack as well as OCCT drops 7~8°C lower with this cooler than with SpinQ. At the same time, Thermalright SI-128 SE equipped with a wider 38 mm fan outperforms ASUS cooler by 3-7°C. Even though the Thermalright cooler can’t boast the same unique looks like ASUS Royal Knight, it still cools processors much better.

Now let’s check out the acoustic performance of our today’s testing participants:

As you can see, almost all coolers generate very moderate noise that doesn’t go past the subjective acoustics comfort zone. The only exception is Thermaltake SpinQ at the maximum turbine rotation speed. It starts producing very loud rumbling sounds starting at ~1200 RPM. You can clearly hear this noise against the background of a quiet system case. Overall, ASUS Royal Knight turned out a quieter cooler, however, things were not so rosy with it, too. I am talking about heatsink plates tinkling against the heatpipes and one another at maximum fan rotation speed. It could be the issue of this particular sample, so I do not dare decrown the entire ASUS Royal Knight family at this point. Nevertheless, I couldn’t really disregard these unpleasant metallic sounds.