For testing power consumption, we took our test system and plugged it
into a Kill-A-Watt power meter. For idle numbers, we allowed the system
to idle on the desktop for 15 minutes and took the reading. For load
numbers we measured the peak wattage used by the system while running
the OpenGL benchmark FurMark 1.10.1 at 1024×768 resolution. We also ran four game titles at 1920×1080 and averaged the peak results recorded the highest Wattage seen on the meter for the gaming results.
Power Consumption Results: The MSI GeForce GTX 660 OC managed to pull slightly less power than the EVGA GeForce GTX 660 SC during our gaming and Furmark testing. It isn’t a huge difference though and is partly due to the fact that its clock speeds are lower (lower voltages) and the custom PCB design that features a different PWM setup. During our Furmark runs, the MSI GeForce GTX 660 OC pulled 296 Watts while the EVGA GeForce GTX 660 SC was pulling 298 Watts. Taking the average of four games gave the MSI GeFoce GTX 660 OC an average power consumption 9 Watts lower than the EVGA counterpart which averaged 299 Watts. All of these cards are very power efficient compared to what we were using just several years ago.