Before getting right to the main tests, I want to show you some other results. Our readers have asked that we perform our cooler tests without overclocking our CPU since overclockers are but a small share of PC users. So, I performed such this kind of a test using four coolers. Here are the results:
Although I didn't overclock it and turned off Hyper-Threading technology, the six-core Intel processor proves to be able to show us the difference between the coolers. However, the temperature of the hottest CPU core is no higher than 70°C even with the worst cooler which is the Arctic Freezer 13 at 1200 RPM. When used in the PWM mode, the cooler becomes 5°C more efficient, yet still inferior to the more expensive Zalman CNPS9900 MAX at 1010 RPM. The difference is about 2°C.
The Zalman CNPS9900 MAX, in its turn, is 3°C worse than its cousin CNPS10X Performa at a rather quiet speed of 1020 RPM but beats the latter in the PWM mode at the max speed of 1530 RPM. The Zalman CNPS10X Performa at max speed outperforms the CNPS9900 MAX by 3°C, though. The Thermalright Archon, even though somewhat insulted at having to cool a non-overclocked CPU, outperformed the rest of the coolers in terms of CPU temperature as well as noise because the max speed of its default Thermalright TY-140 fan is only 1290-1300 RPM.
Next, let’s see how good the coolers are when the CPU is overclocked to 4.2 GHz.
The differences between the coolers are now clearer. We can see that the Arctic Freezer 13 in the quiet mode (1200 RPM) can but barely cope with the 4.2GHz six-core CPU but lowers the temperature by 5°C in the PWM mode. In fact, this is the maximum overclocking limit for the new Swiss cooler.
Working at 1010 RPM, the Zalman CNPS9900 MAX was 2°C better than the Freezer 13 with the non-overclocked CPU and is now 5°C better when the CPU is overclocked. Interestingly, it is also now as good as the Zalman CNPS10X Performa at 1020 RPM. When the PWM control is enabled, the Zalman CNPS9900 MAX lowers the temperature of the hottest CPU core by 7°C, which is quite good for a 580RPM increase in speed. On the other hand, the CNPS10X Performa can lower that temperature by as much as 12°С when working at its full speed (+1040 RPM) and get ahead of the CNPS9900 MAX by 5°C. The tower-design cooler is louder then, of course.
So if you want less noise, you should take a look at the Thermalright Archon with its large and high-quality TY-140 fan. Take note of the large difference in the performance of this cooler at 800 RPM and maximum speed when cooling the overclocked CPU. It amounts to 9°C. Anyway, the Archon proves its superiority even though the CPU is still not hot enough for this super-cooler to show its best.
I can add to these results that I could overclock my six-core CPU with the Zalman CNPS9900 MAX cooler at 1740 RPM to a clock rate of 4.37 GHz with a voltage of 1.425 volts. The maximum temperature of the hottest CPU core was 89°C then.
As we see, Zalman CNPS10X Performa with its default fan running at 2060 RPM cools the CPU better by 8°C:
...and the Thermalright Archon is as much as 13°C better using one TY-140 fan at 1300 RPM:
So, the Zalman CNPS9900 MAX is quite good in itself. Its predecessor CNPS9900 LED of the same design could not deliver such performance. Of course, the price factor should also be taken into account as I will do in the Conclusion. Right now let’s see how much noise the coolers produce.