Cooling Efficiency and Acoustic Performance
You may have already noticed that we are using two mainboards and two CPUs today. At first we were going to run all tests with two processors on the same Gigabyte GA-X38-DQ6 mainboard. However, for some reason this board wouldn’t start with the quad-core Intel Core 2 Extreme QX9650 processor, although they used to work perfectly fine together before. Therefore, we decided to test the liquid-cooling system and the air-cooler with a dual-core Intel Core 2 Duo E8400 on Gigabyte GA-X38-DQ6 mainboard and with a quad-core CPU on ASUSTek P5K Deluxe mainboard.
So, with the fan of Thermaltake PW 850i ProWater working at its slowest speed, we managed to overclock our dual-core processor to 4266MHz with 1.55V Vcore:
The quad-core processor overclocked to 3900MHz with 1.575V Vcore:
The results for both, the liquid-cooling system and its air competitor, are given on the chart below:
Thermaltake PW 850i ProWater copes pretty well with an overclocked dual-core processor, although it still loses to one of the today’s best super-coolers in both fan modes. However, the quad-core processor appeared an impossible nut to crack. Thermaltake PW 850i ProWater loses much more seriously to the air cooler. Besides, we couldn’t reach the maximum CPU frequency with this cooling system at all. Thermalright SI-128 SE won about 11ºC in quiet mode and at maximum fan rotation speed the gap reduces to 7ºC, which indicates that the radiator of the liquid-cooling system is pretty weak and cannot dissipate the heat efficiently enough.
Unfortunately, Thermaltake PW 850i ProWater turned out pretty noisy. At minimal fan rotation speed of ~1310RPM you can clearly hear the pump (35.9dBA/1m) even though the pump and expansion tank block was installed inside a closed system case with special noise insulation using soft polyurethane foam padding. If we had attached the pump to the bottom of the system case, as the guide recommended, the noise level could have been much higher. As for the maximum fan rotation speed of ~2370RPM, it is louder than the pump reaching an extremely uncomfortable level of 42.9dBA/1m.