First we want to check out our liquid cooling systems in their standard configurations on a 4.375GHz CPU. You can see the results in the following table as well as in the diagram below:
As opposed to low-end liquid cooling systems, these products can challenge the best air cooler. The Corsair Hydro H100i Extreme Performance with its large radiator is ahead in the standard configuration. It is more efficient than the air cooler not only at top or medium speeds of its two Corsair SP120L fans but also at 1000 and even at 800 RPM. On the other hand, it is not so extraordinary for a liquid cooling system to be 1 or 2°C better than an air cooler (even though the best one) – we mean the Corsair H100i’s 2x1200 RPM mode vs. the Phanteks PH-TC14P?’s 2x1300 RPM mode. Well, we have more tests today, so our opinion may change yet.
The three products with thick 120mm radiators are almost equal in their performance. At the maximum speed of the fans, the Thermaltake Water 2.0 Pro, Corsair Hydro H80i High Performance and Zalman LQ320 ensure the same CPU temperature at peak load. The Corsair seems to accomplish this by means of its higher-speed fans, so the Zalman LQ320 looks preferable to its opponents. The Thermaltake Water 2.0 Pro is somewhat better than the Corsair H80i, Zalman LQ320, and even than the Phanteks PH-TC14P? at 1600 and 1200 RPM but the Corsair H80i catches up with it at 1000 RPM, the Zalman LQ320 being a mere 1°C behind.
The Thermaltake Water 2.0 Performer, the most efficient product in the first part of our testing, is 2 to 3°C inferior to its cousin, depending on fan speed.
Now we will check the coolers out with alternative fans from Corsair (the Corsair Hydro H80i High Performance performs unmodified). Here are the table and the diagram:
The Corsair Hydro H100i Extreme Performance enjoys a larger advantage over its opponents now that it has four fans. It is also 6°C better than the air cooler at the maximum speed of the fans and 2°C better at 1000 RPM. The Zalman LQ320 joins the under-70°C club, too, the two alternative fans increasing its performance significantly. We can note that the Zalman is 2 to 4°C ahead of its immediate opponents from Corsair and Thermaltake at 1600, 1200 and 1000 RPM, although the Thermaltake Water 2.0 Pro seems to have the same design. And finally, take note that the Water 2.0 Pro performs worse with two Corsair SP120 fans than in its default configuration.
Now we overclock our CPU to 4.5 GHz at 1.435 volts and check out the efficiency of every cooler again in their standard configurations as well as with the alternative fans. Here are the table and the diagram:
The Corsair Hydro H100i Extreme Performance is unrivalled in this test session but the Phanteks PH-TC14P? is only 1°C behind at 1000 RPM. The same gap can be observed when the Phanteks and the Corsair have fan speeds of 1300 and 1200 RPM, respectively. We don’t take the noise factor into account, though. Other things being equal, the Corsair has much quieter fans than the Phanteks. We’ll discuss this shortly.
The Zalman LQ320 and the Corsair Hydro H80i High Performance can also be noted as capable of coping with the overclocked CPU. They are closely followed by the Thermaltake Water 2.0 Pro. None of these liquid cooling systems could cool our six-core CPU overclocked to 4.5 GHz at 1.435-1.445 volts when their fan speed was 1200 RPM and the CPU ran LinX.