Cooling System: Efficiency and Noise
The original cooling system installed on the EVGA GeForce GTX 680 SC Signature 2 has no proper name, unlike many other original coolers, yet this doesn’t make it any worse. First of all, we must note that this EVGA cooler fits within the dimensions of the reference GeForce GTX 680 and blocks only one adjacent PCIe slot on the mainboard. Then, it is simple in design, which must be the reason why the graphics card doesn't cost much more than ordinary GeForce GTX 680s.
So, the cooler consists of a nickel-plated dual-section heatsink and a plastic casing with fans:
There are four heat pipes, 8 millimeters in diameter, piercing through the whole length of the heatsink. The main heatsink is rather slim and light and has a hollow for one of the fans.
The auxiliary heatsink is made of aluminum fins soldered to the pipes. The pipes are soldered to the cooler’s base as well, even though it’s hard to see any trace of soldering there.
The whole arrangement is cooled by two fans installed in the plastic casing.
The fans are 80 millimeters in diameter (the impellers are 75 millimeters actually), but their increased height (15 millimeters instead of the conventional height of 10 to12 millimeters) helps them produce higher pressure and ensure higher performance at low speeds.
The 9-blade impellers were manufactured by Power Logic. Their part number is PLA08015S12HH:
As is indicated on the label, the fans run on sleeve bearings. Their speed is PWM-regulated from 1100 to 4170 RPM (according to our monitoring tools). The peak power consumption of each fan is no higher than 4.2 watts.
We checked out the card’s temperature during five consecutive runs of Aliens vs. Predator (2010) game with the highest image quality settings in 2560x1440 resolution with 16x anisotropic filtering and MSAA 4x antialiasing):
We used MSI Afterburner 2.2.3 and GPU-Z 0.6.4 as monitoring tools. This test was performed inside a closed system case at 22°C room temperature. All thermal tests were carried out before we took the card apart, i.e. with its default thermal interface still intact.
Here is how this cooler copes with the EVGA GeForce GTX 680 SC Signature 2:
Auto fan mode
Max fan speed
The GPU temperature is 74°C with the fans regulated automatically. The number doesn’t look impressive, but check out the peak speed of the fans. It is only 1440 RPM. We’ll see shortly how quiet this is, but subjectively the EVGA GeForce GTX 680 SC Signature 2 didn’t seem to disturb the quiet of our testbed. At the maximum speed of the fans the card is of course loud, but the GPU is as cool as 53°C under peak load. So, the original cooler from EVGA is highly efficient, now let’s check out how noisy it is.
The noise level of each cooler was measured after 1:00 AM in a closed room about 20 m2 big using CENTER-321 electronic noise meter. The noise level for each cooler was tested outside the system case when the only noise sources in the lab were the cooler and its fan. The noise meter was installed on a tripod and was always at a 150 mm distance from the cooler fan rotor. The tested cooling systems were placed at the edge of the desk on a sheet of polyurethane foam. The lowest noise reading our noise meter device can register is 29.8 dBA and the subjectively comfortable noise level in these testing conditions was around 36 dBA (do not mix it up with low noise level). The fans rotation speeds were adjusted in the entire supported range using our in-house controller by changing the voltage with 0.5 V increment.
We’ll test the EVGA GeForce GTX 680 SC Signature 2 against reference Nvidia GeForce GTX 680 and AMD Radeon HD 7970 cards as well as against an ASUS GeForce GTX 680 DirectCU II TOP which features one of the quietest coolers we’ve ever seen. The vertical dotted lines mark the speed of the fans in the automatic regulation mode. Here are the results:
Although the noise graph of the EVGA GeForce GTX 680 SC Signature 2 goes close to the noise graph of the reference AMD Radeon HD 7970 which is rather loud, the EVGA is much quieter. Why? Take note of the peak speed of the fans in the automatic regulation mode. The AMD Radeon HD 7970 can get as loud as 59 dBA with its fans regulated automatically whereas the EVGA card produces only 41 dBA of noise then (measured from a distance of 15 centimeters, by the way). The difference is huge. The EVGA cooler is also quieter than the reference GeForce GTX 680 but cannot beat the DirectCU II cooler from ASUS. The latter remains the quietest solution we’ve ever seen on mass-produced graphics cards, perhaps being only inferior to the Arctic Xtreme series.