Cooling Efficiency Tests

We started our cooling efficiency tests of Swiftech H₂0-220 Apex Ultra+ liquid-cooling system with maximum CPU overclocking using OCCT utility. It turned out that this system with the fans working in quiet mode (~900RPM) keeps the CPU stable at up to 4.05GHz speed with the Vcore set to 1.6V in the mainboard BIOS (1.56~1.58V according to monitoring data). The most remarkable thing is that the temperatures of the hottest processor die didn’t exceed 58°C:

The result is more than impressive. And at maximum fan rotation speed of ~2000RPM the temperature got another 2°C lower and never exceeded 56°C. But what will the results be if we use Linpack instead of the OCCT to load the processor? In this case we had to lower the CPU frequency to 3.95GHz at the same voltage setting. After 15 test cycles the temperature under maximum workload reached 72°C in quiet mode and 70°C with the fans of Swiftech H₂0-220 Apex Ultra+ working at their full speed. I have to add that these results were obtained with a graphics card water block installed and working.

Now I have to say a few words about maximum processor overclocking using the highly efficient air cooler that is trying to compete against a liquid-cooling solution today. We reached 4.04GHz with 1.6V Vcore and 67°C peak temperature, which is 9°C lower than the temperature provided by the liquid-cooling solution from Swiftech:

The difference doesn’t seem to be too dramatic, but Linpack tests showed that Thermalright IFX-14 with two 140-mm fans can only provide enough cooling for the CPU to overclock to 3.92GHz at 80°C, which is 30MHz and 8/10°C worse than provided by the liquid-cooling system.

The diagram below sums up all these results, disregarding the difference in CPU overclocking:

As to the graphics card cooling, Swiftech H₂0-220 Apex Ultra+ proved even more impressive. RV770 GPU on our Radeon HD 4850 equipped with MCW60 water block overclocked from the nominal 625MHz to 765MHz and its temperature didn’t exceed 32°C under peak workload:

Not bad, isn’t it? By the way, the graphics card itself warmed up considerably less, even though all other components were cooled by means of natural convection. In the same testing conditions one of the best air coolers for graphics cards, Arctic Cooling Accelero S1 with a Turbo-Module could ensure graphics card stability only at 750MHz frequency at 55°C.

It is not quite correct to sum up the thermal advantage of Swiftech H₂0-220 Apex Ultra+ against two high-end air coolers, however, on the other hand, the liquid-cooling system cooled both components – CPU and GPU - at the same time. So, I guess, we can say that Swiftech H₂0-220 Apex Ultra+ turned out 21~23°C more efficient than “air” (-13/14°C GPU and -9/11°C CPU) depending on the operational mode of the liquid-cooling system.

We also have to say a few words about the acoustic performance of the Swiftech H₂0-220 Apex Ultra+ system. In fact, everything here is very simple, because at the minimal radiator fans rotation speed of ~900RPM you can only hear low rumbling of the pump. This operational mode is not completely noiseless, but definitely very quiet. Besides, you will most likely lower the noise by using a shock absorbing pad. With two 120-mm fans at their maximum speed the acoustics is hardly comfortable, however since the temperature difference between the two modes doesn’t exceed 2°C, I don’t think you will really use this mode that much.

Conclusion

Certainly, Swiftech H₂0-220 Apex Ultra+ performed brilliantly in our today’s test session. It confidently defeated the best air coolers in our tests, and the only thing that may slightly cloud this indisputable success is the price of ~380 that you will have to pay for it and not completely noiseless pump operation. However, these two things will hardly discourage dedicated overclocking fans who are no longer satisfied with the air coolers efficiency and are not excited about a DIY solution. If we compare Swiftech H₂0-220 Apex Ultra+ with any DIY solutions of similar efficiency, even if the latter turn out better (which I strongly doubt), Swiftech’s solution has one indisputable advantage: it is ready to go right from the box. You don’t have to search for components, wait for some parts on backorder, make sure everything fits right and then invent a solution and put it all together on your own. The only thing you need to do once you get your new Swiftech H₂0-220 Apex Ultra+ out of the box is carefully install all components and connect them with one another. And here you go: you’ve got an excellent liquid-cooling system with remarkable efficiency and low noise.