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 measurements were taken outside the system case, when the only noise source was the cooling system and its fans. The noise-level meter was set on a tripod at a distance of 15 centimeters from the graphics card cooler fan rotor. The mainboard with the graphics card was placed at the edge of a desk on a foam-rubber tray. The bottom limit of our noise-level metering device 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 cards’ fans was changed with the help of a special controller supporting 0.5 V voltage adjustment increments.
The Nvidia GeForce GTX 650 Ti, EVGA GeForce GTX 650 Ti SSC and both cards from ZOTAC have no fan speed monitoring, so we constructed their graphs by extrapolating the maximum fan speed (according to the specs) to lower voltages. Of course, that’s not a very accurate approach since the correlation between speed and voltage is not linear, but we didn’t have any other method. Here are the results:
According to the diagram, Zotac’s GeForce GT 640 and GeForce GTX 650 Ti AMP! Edition seem to be the quietest cards, but we should also note their fan speed during the temperature test. While the Zotac GeForce GT 640 is indeed quieter than the other four cards in this review, the Zotac GeForce GTX 650 Ti AMP! Edition is subjectively as loud as the cards from Nvidia and EVGA, all of them being rather uncomfortable.
The Gigabyte WindForce 2X cooler works at 1600 RPM in the automatic fan regulation mode, so it is quieter than the others, including the Zotac GeForce GT 640. The Gigabyte was also absolutely silent when idle whereas the Zotac GeForce GT 640, for example, was audible with its small but irritating fan against the background noise of our quiet testbed.
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 (three runs of the Metro 2033: The Last Refuge benchmark at 2560x1440 with maximum image quality settings, but without antialiasing).
For comparison purposes we also added the results for MSI GeForce GTX 660 2 GB, Sapphire Radeon HD 7850 2 GB and AMD Radeon HD 7770 1 GB. Let’ see what we got:
As you can see, our configuration with an overclocked six-core CPU needs less than 400 watts irrespective of the graphics card. It needs only 278 watts with the GeForce GT 640. The Radeons consume more power than their opponents, but not by much. The configurations with different GeForce GTX 650 Ti cards don’t differ much in their power requirements, but the EVGA GeForce GTX 650 Ti SSC needs more power than the overclocked Gigabyte. We can also note that the GeForce GTX 660 2GB configuration needs 62 watts more than the GeForce GTX 650 Ti 1GB configuration.
All the configurations are comparable to each other in terms of their power draw in idle mode.