Cooling System: Efficiency and Noise
Besides the reinforced power system and pre-overclocked GPU and memory, the Palit GeForce GTX 680 Jetstream features an original cooler which has a large aluminum heatsink with four copper heat pipes.
Three of the pipes are 6 millimeters in diameter whereas the fourth pipe, which is separate from the others and serves the back part of the heatsink, is 8 millimeters. The pipes are soldered to the heatsink fins as well as to the nickel-plated copper base of the cooler.
There’s a layer of thick gray thermal grease on the GPU die.
The power components and memory chips are cooled by means of a metallic plate with thermal pads.
The cooler has three fans installed in the plastic frame:
The central fan is 90 millimeters in diameter whereas the other two are 80 millimeters. The fans are all manufactured by Power Logic Tech and run on fluid dynamic bearings.
The speed of the fans is PWM-regulated within a range of 900 to 2700 RPM. The 90mm fan in the middle features blue highlighting.
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 antialiasing).
We used MSI Afterburner 2.2.0 and GPU-Z 0.6.2 as monitoring tools. This test was carried out with a closed system case at an ambient temperature of 23°C. We didn’t change the card’s default thermal interface.
Let’s see what temperature the card has when its fans are regulated automatically and at the maximum speed of the fans:
So, in the automatic regulation mode the GPU temperature was 78°C, which isn’t much for a pre-overclocked GTX 680. Considering that the peak speed of the fans was only 1720 RPM, the result is just excellent. We can remind you that the reference GeForce GTX 680 at the default clock rates and under the same conditions gets as hot as 81°C and has a fan speed of 2460 RPM. So again, the Palit’s result is impressive indeed. When the fans were set at their maximum speed of 2610 RPM, the GPU of the Palit card was no hotter than 64°C.
Then we measured the level of noise using an electronic noise-level meter CENTER-321 in a closed and quiet room about 20 sq. meters large. The noise-level meter was set on a tripod at a distance of 15 centimeters from the graphics card which was installed on an open testbed. The mainboard with the graphics card was placed at an edge of a desk on a foam-rubber tray.
The bottom limit of our noise-level meter is 29.8 dBA whereas the subjectively comfortable (not low, but comfortable) level of noise when measured from that distance is about 36 dBA. The speed of the graphics card’s fan was being adjusted by means of a controller that changed the supply voltage in steps of 0.5 V.
We’ve included the results of reference GeForce GTX 680 and Radeon HD 7970 cards into the next diagram for the comparison’s sake (the vertical dotted lines indicate the top speed of the fans in automatic regulation mode):
The picture is more complicated here. The noise graph of the Palit GeForce GTX 680 Jetstream goes higher than the graphs of the reference GeForce GTX 680 and Radeon HD 7970. But if we compare the coolers in the automatic fan regulation mode, we can see that the Palit is no louder than the reference GTX 680 (51 against 52 dBA) and much better than the Radeon HD 7970 (51 against 59 dBA). So, the Palit GeForce GTX 680 Jetstream is actually quieter than the two reference card in 3D applications, but we have to confess that it’s louder than its opponents in 2D mode and is even louder than the subjectively comfortable level. In other words, the Palit’s cooler is audible against the background noise of the quiet system case in 2D mode. That’s a serious downside in our opinion. Hopefully, Palit will release a BIOS update with a lower fan setting for 2D applications.