|ASUS GeForce GTX 660Ti DirectCU-II TOP|
|Reviews - Featured Reviews: Video Cards|
|Written by Olin Coles|
|Thursday, 16 August 2012|
Page 12 of 14
VGA Power Consumption
In this section, PCI-Express graphics cards are isolated for idle and loaded electrical power consumption. In our power consumption tests, Benchmark Reviews utilizes an 80-PLUS GOLD certified OCZ Z-Series Gold 850W PSU, model OCZZ850. This power supply unit has been tested to provide over 90% typical efficiency by Chroma System Solutions. To measure isolated video card power consumption, Benchmark Reviews uses the Kill-A-Watt EZ (model P4460) power meter made by P3 International. In this particular test, all power consumption results were verified with a second power meter for accuracy.
The power consumption statistics discussed in this section are absolute maximum values, and may not represent real-world power consumption created by video games or graphics applications.
A baseline measurement is taken without any video card installed on our test computer system, which is allowed to boot into Windows 7 and rest idle at the login screen before power consumption is recorded. Once the baseline reading has been taken, the graphics card is installed and the system is again booted into Windows and left idle at the login screen before taking the idle reading. Our final loaded power consumption reading is taken with the video card running a stress test using graphics test #4 on 3DMark11. Below is a chart with the isolated video card power consumption (system without video card subtracted from measured combined total) displayed in Watts for each specified test product:
* Results are accurate to within +/- 5W.
Because this article discusses a factory-overclocked ASUS GeForce GTX 660 Ti DirectCU-II TOP video card, our power consumption results are not representative of GTX 660-series products that use the reference design. Both the reference design and the ASUS GeForce GTX 660 Ti DirectCU-II TOP accept two 6-pin PCI-E power connections for normal operation, and will not activate the display unless proper power has been supplied. NVIDIA recommends a 450W power supply unit for stable operation with GTX 660 Ti, which should include both required 6-pin PCI-E connections without the use of adapters. In our test results the ASUS GeForce GTX 660 Ti DirectCU-II TOP consumed only 13W at idle, and 154W under full load.
If you're familiar with electronics, it will come as no surprise that less power consumption equals less heat output as evidenced by our thermal results below...
GeForce GTX 660 Ti Temperatures
This section reports our temperature results subjecting the video card to maximum load conditions. During each test a 20°C ambient room temperature is maintained from start to finish, as measured by digital temperature sensors located outside the computer system. GPU-Z is used to measure the temperature at idle as reported by the GPU, and also under load.
Using a modified version of FurMark's "Torture Test" to generate maximum thermal load, peak GPU temperature is recorded in high-power 3D mode. FurMark does two things extremely well: drives the thermal output of any graphics processor much higher than any video games realistically could, and it does so with consistency every time. Furmark works great for testing the stability of a GPU as the temperature rises to the highest possible output.
The temperatures illustrated below are absolute maximum values, and do not represent real-world temperatures created by video games or graphics applications:
As you've seen us mentioned on the pages leading up to this section, NVIDIA's Kepler architecture yields a much more efficient operating GPU compared to previous designs. This becomes evident by the extremely low idle temperature, and translates into modest full-load temperatures. Even more impressive is how quiet the ASUS GeForce GTX 660 Ti DirectCU-II TOP operates, barely changing levels from silent to almost silent as it reaches full load. With an open computer case and my ear positioned only a few inches from the video card, fan noise was almost non-existent under loaded operation. Manually turning up fan power to 100% with utilities such as ASUS GPU Tweak, fan noise was extremely low and only slightly audible.
The ASUS GeForce GTX 660 Ti DirectCU-II TOP video card is by far the least audible graphics product I've ever tested, and at up to moderate load it's indistinguishable from passive cooled products.