Noise Level and Power Consumption
The noise level of each cooler was measured between 1:00 and 3:00 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 fan(s) rotation speed was adjusted in the entire supported range using our precise in-house controller by changing the voltage with 0.5 V increment.
The vertical dotted lines mark the peak speed of the coolers’ fans in the automatic speed regulation mode. Here’s the diagram:
Although the noise level graphs of the MSI and Palit go higher than the reference GeForce GTX 780's, only one of them is noisier in 3D applications. It is the Palit GeForce GTX 780 JetStream as you can easily see by the dotted line that shows the peak speed of the fans in the automatic regulation mode. But, frankly speaking, Palit's cooler is not very different from Nvidia's. The MSI GeForce GTX 780 OC Gaming, on its part, is quieter than both its opponents and is more comfortable subjectively, yet it can only be called silent in 2D applications. That said, we are still very fond of the MSI Twin Frozr IV cooler which is currently one of the best solutions available in terms of performance/noise ratio.
We measured the power consumption of our testbed equipped with different graphics cards using a multifunctional Zalman ZM-MFC3 panel which can report how much power a computer (without the monitor) draws from a wall outlet. There were two test modes: 2D (editing documents in Microsoft Word or web surfing) and 3D. In the latter case the load was created by four runs of the introductory “Swamp” scene in Crysis 3 game at 2560x1440 with maximum image quality settings, but without MSAA.
In our today’s power consumption tests we compare the original GeForce GTX 780s with two SLI-linked GTX 780s (at the same frequencies of 980/6208 MHz), AMD Radeon HD 7990 and Nvidia GeForce GTX 690 (we’ll use these dual-processor cards in our performance benchmarks as well).
It is the 2-way SLI configuration with two overclocked GeForce GTX 780s that needs the most power. It requires 114 watts more at peak load than the Nvidia GeForce GTX 690 configuration and 22 watts more than the dual-processor AMD Radeon HD 7990. The difference from the single GeForce GTX 780 is 223 watts, which is close to the specified power consumption of one GTX 780 (250 watts). We can also note that the difference between the configurations with the two GeForce GTX 780 cards from MSI and Palit is only 11 watts. It is due to the difference in the cards’ clock rates.