Cooling Efficiency Tests
During OCCT tests inside a closed system case using the “weakest” cooling system of the today’s testing participants we managed to overclock our quad-core processor to 3.95 GHz (+31.7%). The nominal processor Vcore was increased to ~1.55 V in the mainboard BIOS (+24.0%).
According to monitoring data, the CPU core voltage was a little lower than what was set in the mainboard BIOS, namely around 1.50~1.54 V. When we launched Linpack 32-bit we had to lower the frequency to 3.85GHz to ensure stability at the same Vcore setting:
Before we start checking out the obtained results we need to draw your attention to Arctic Cooling Freezer Xtreme cooler. The reason for that is pretty simple: the fan of the cooler sample we received for testing wasn’t working correctly. No matter if we enabled or disabled PWM adjustment mode (we even physically disconnected the fourth pin in the four-pin connector), the fan rotation speed remained constant and stayed at the minimal ~500 RPM. This speed ensured extremely quiet operation of the cooler, but was critically low for efficient cooling of an overclocked CPU. In this quiet operational mode the new Freezer Xtreme could only cope with a CPU overclocked to 3.75GHz at 1.4V Vcore, which is a fairly modest result against the background of other today’s testing participants. So, we decided not to limit the potential of the Freezer Xtreme cooler by an improperly working fan and tested it with a Scythe Slip Stream 120 fan working at the same speeds as on Thermalright IFX-14. The fan was fastened between the heatsink arrays using two flexible rubber bands.
So, let’s check out the obtained results:
The results of our today’s test session turned out very interesting. ASUS Lion Square with automatically adjusted fan rotation speed turned out as efficient as Arctic Cooling Freezer Xtreme with an alternative fan in quiet mode at ~910 RPM. Overall, the “lion” doesn’t impress us with its efficiency, although it keeps a quad-core processor stable at 3.85GHz even under severe Linpack conditions. As we have expected, the winner in quiet mode is Thermalright IFX-14, outperforming its rivals by 5-6°C inside the system case and by 7°C in an open testbed. Note that the efficiency difference between the coolers of the same type inside the system case and in an open testbed remained the same (taking into account overall lower temperatures in the open testbed).
However, as soon as you double the rotation speed of the Arctic Cooling Freezer Xtreme fan, the cooling efficiency with an overclocked processor improves by 10-11°C and it even outperforms Thermalright IFX-14 by 1°C inside the system case and gets dangerously close to it in an open testbed! Freezer Xtreme has a very dense heatsink (only ~1.8 mm between the heatsink plates) that is why we did expect its efficiency to improve with the increase of the fan rotation speed. Note that both leading cooling solutions use the same fan, so in fact it is the competition of two heatsinks with similar design. Freezer Xtreme features 6-mm heatpipes, while IFX-14 – 8-mm ones. Besides, the latter is almost twice as expensive as the Arctic Cooling solution and is larger in size. Well, I have to admit that after a simple modification the new Arctic Cooling Freezer Xtreme managed to really surprise us. I only wish I could fit a 32/38 mm fan between its heatsink arrays…
I am not going to offer you the results of our acoustic measurements this time, because everything here is fairly simple. In quiet mode you cannot hear the 92-mm fan of the ASUS Lion Square at its modest ~800 RPM. And under workload when it speeds up to ~2280 RPM, you can hear it, but it is not annoying in any way (36.2 dBA at 1m). As for the acoustics of the Scythe Slip Stream fan, we have already discussed it in our 120-mm fans roundup. As I have already said before, you can’t hear the original Arctic Cooling Freezer Xtreme fan in its quiet mode at ~500 RPM. Unfortunately, it didn’t work and at maximum ~1500 RPM.