Cooling System Design and Efficiency
There is nothing original about the GeForce GTX 680’s cooler. It is based on a modest-sized aluminum heatsink with slim fins.
According to available documentation, the heatsink has three copper heat pipes in its base that help distribute the heat uniformly in the aluminum base and fins.
The GPU is only contacted by the cooler’s copper sole which is quite satisfactorily finished:
The power components and memory chips are cooled by a metallic plate with thermal pads:
A classic centrifugal fan with a diameter of 80 millimeters is employed in this cooler:
Nvidia claims that the use of high-quality materials and individually balanced fans helps keep the noise level 5 dBA lower compared to the Radeon HD 7970. We’ll check this out shortly.
The speed of the fan is PWM-regulated within a range of 1000 to 4200 RPM, the latter number being just 85% of the fan’s full speed. We tried to regulate the fan manually and found its top speed to be 5200 RPM. Nvidia thinks that 4200 RPM is enough to cool the 28nm GPU chip, though.
We checked out the card’s temperature while running Aliens vs. Predator (2010) in five cycles at the highest settings (2560x1600, with 16x anisotropic filtering and 4x full-screen antialiasing). We used EVGA PrecisionX version 3.0.0 Beta 20 and GPU-Z 0.5.9 as monitoring tools, the latter reporting the temperature and fan speed of the GeForce GTX 680 correctly. This test was carried out with a closed system case at an ambient temperature of 26°C. We didn’t change the card’s default thermal interface.
Here is the temperature of the card in the automatic fan regulation mode and at 85% speed:
Automatic fan mode
85% fan speed
So, the GPU was as hot as 81°C in the automatic regulation mode, the fan speed rising from 1100 to 2460 RPM. At the top speed of 4200 RPM the temperature was no higher than 62°C. Now what about noise?